Commonwealth, Aplt. v. Herman, J. , 639 Pa. 466 ( 2017 )


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  •                                    [J-124-2016]
    IN THE SUPREME COURT OF PENNSYLVANIA
    MIDDLE DISTRICT
    SAYLOR, C.J., BAER, TODD, DONOHUE, DOUGHERTY, WECHT, MUNDY, JJ.
    COMMONWEALTH OF PENNSYLVANIA,                 :   No. 74 MAP 2016
    :
    Appellant                   :   Appeal from the Order of the York
    :   County Court of Common Pleas,
    :   Criminal Division, at No. CP-67-CR-
    v.                               :   0002400-2014 dated 2/10/15
    :
    :
    JOEY WAYNE HERMAN,                            :
    :
    Appellee                    :   ARGUED: December 7, 2016
    OPINION
    CHIEF JUSTICE SAYLOR                                    DECIDED: May 25, 2017
    This is a direct appeal by the Commonwealth in a case involving Appellee’s
    alleged possession and delivery of a chemical compound claimed to be either a
    controlled substance or a designer drug. A central issue is whether the portions of the
    Controlled Substance, Drug, Device and Cosmetic Act under which Appellee was
    charged – relating to “analogues” of scheduled controlled substances, as well as
    “substantially similar” designer drugs – are unconstitutionally vague.
    I. Background
    At all relevant times, Appellee owned and operated a smoke shop in York
    County. On April 17, May 30, and July 11, 2013, undercover police officers entered the
    shop and purchased small packets of substances having brand names such as “Winter
    Haze” and “V-8 Air Freshener.” Laboratory testing performed for the Commonwealth by
    Michael Coyer, PhD – a forensic toxicologist and the Commonwealth’s eventual expert
    witness – revealed that these products contained the chemical PB-22, which the
    prosecution alleged to be either a controlled substance as an “analogue” of the known
    synthetic cannabinoid JWH-018,1 or a designer drug. On July 15, 2013, the police
    executed search warrants at Appellee’s residence and business. At each location they
    seized additional packets of substances containing PB-22.       Appellee was charged,
    under the Controlled Substance, Drug, Device and Cosmetic Act (the “Act”),2 with three
    counts of delivery of a controlled substance, one count of possession with intent to
    deliver a controlled substance, and one count of possession, or possession with intent
    to distribute, a designer drug. See 35 P.S. §780-113(a)(30), (36).3
    1
    Synthetic cannabinoids are artificial compounds that mimic the effects of natural
    cannabinoids found in marijuana by interacting with the body’s cannabinoid receptors,
    denominated as “CB1” and “CB2.” See generally United States v. Hossain, 
    2016 WL 70583
    , *1 (S.D. Fla. Jan. 5, 2016) (sentencing order) (discussing the operation of
    synthetic cannabinoids in the human body). Information in the record suggests that the
    CB1 receptor is responsible for the body’s psychoactive response, whereas the CB2
    receptor “is associated with the immune system and is responsible for some of the
    proposed therapeutic qualities of cannabinoids.” Report of Mark S. Erickson, PhD, at 1.
    2
    Act of Apr. 14, 1972, P.L. 233, No. 64 (as amended 35 P.S. §§780-101 to 780-144).
    3
    Those provisions state:
    (a) The following acts and the causing thereof within the Commonwealth
    are hereby prohibited:
    * * *
    (30) . . . the . . . delivery, or possession with intent to . . .
    deliver, a controlled substance . . ..
    * * *
    (36) The knowing or intentional . . . possession with intent to
    distribute, or possession of a designer drug. . . .
    35 P.S. §780-113(a)(30), (36).
    [J-124-2016] - 2
    Before describing the procedural history, it is helpful to review the legislation,
    including a material revision made in early July 2013, between the second and third
    undercover purchases. See Act of July 2, 2013, P.L. 242, No. 40 (“Act 40”). In relevant
    part, the Act defines a controlled substance as a substance listed in Schedules I
    through V of the Act. See 35 P.S. §780-102.4 These are known as “scheduled” drugs.
    See, e.g., 40 P.S. §908-1.     It defines designer drug as “a substance other than a
    controlled substance that is intended for human consumption and that either has a
    chemical structure substantially similar to that of a controlled substance in Schedules I,
    II or III . . . or that produces an effect substantially similar to that of a controlled
    substance in Schedules I, II or III.” 35 P.S. §780-102.5 The schedules are set forth in
    the Act, see 35 P.S. §780-104, although only Schedule I is relevant to this dispute.6
    Act 40 amended the description of Schedule I.          In both the pre- and post-
    amendment timeframes, Schedule I included JWH-018 by name as a synthetic
    4
    The Secretary of Health has authority to add compounds to the schedules via
    regulation. See 35 P.S. §780-103. The schedules as thus augmented are set forth in
    the administrative code. See 25 Pa. Code §25.72. The parties do not suggest that any
    administrative additions to Schedule I are relevant to this case.
    5
    The Commonwealth clarified at the preliminary hearing that, because controlled
    substances and designer drugs are mutually exclusive categories, its decision to lodge
    a designer-drug count against Appellee constituted a “fallback position” in the event PB-
    22 was found not to be a controlled substance. N.T., Apr. 14, 2014, at 50.
    6
    The analogue and/or designer drug provisions in the Act appear to be a legislative
    response to underground laboratories which “have become adept at tinkering with the
    molecular structure of scheduled controlled substances while retaining the effects that
    those substances produce.” United States v. Carlson, 
    2013 WL 5125434
    , at *27 (D.
    Minn. Sept. 12, 2013) (internal brackets, quotation marks, and citation omitted); accord
    Zunny Losoya, Comment, Synthetic Drugs – Emergence, Legislation, and the Criminal
    and Legal Aftermath of Broad Regulation, 66 SMU L. REV. 401, 403 (2013) (noting that
    synthetic drugs arise when chemists “slightly alter . . . existing banned drugs to evade
    the law and sell abusable drugs” (internal quotation marks and footnote omitted)).
    [J-124-2016] - 3
    cannabinoid. See 35 P.S. §780-104(1)(vii)(4) (2011); 
    id. §780-104(1)(vii)(2)(B) (2013).
    In the pre-amendment version, Schedule I encompassed all “analogues” of the named
    synthetic cannabinoids.      See 35 P.S. §780-104(1)(vii) (2011) (subsuming within
    Schedule I “[s]ynthetic cannabinoids or any material, compound, mixture or preparation
    which contains . . . the following substances, including their analogues . . .: . . . (4)
    JWH-018”). With the Act 40 revisions, Schedule I now encompasses compounds which
    are synthetic cannabinoids falling into thirteen specified “chemical designations,” as well
    as analogues of those compounds. Thus, Schedule I now includes:
    Synthetic cannabinoids, including any material, compound, mixture or
    preparation that is not listed as a controlled substance in Schedules I, II,
    III, IV and V, . . . which contains any quantity of the following substances
    [or] their . . . analogues, . . . whenever the existence of these . . .
    analogues . . . i[s] possible within the specific chemical designation . . .
    35 P.S. §780-104(1)(vii) (2013) (emphasis added).7 Only the second specified chemical
    designation is potentially relevant to this matter:
    2. Naphthoylindoles or any compound containing a 3-(-1-naphthoyl)
    indole structure with substitution at the nitrogen atom of the indole ring
    whether or not further substituted in the indole ring to any extent and
    whether or not substituted in the naphthyl ring to any extent. This shall
    include the following: . . . (B) JWH-018. . . .
    
    Id. §780-104(1)(vii)(2)(B) (2013).8
    Notably, the Act has never provided a definition of
    “analogue” or, for the designer-drug provision, “substantially similar.”
    7
    The text states “if possible” rather than “is possible.” This is clearly a typographical
    error: “if possible” does not make grammatical sense, and all other subsections use the
    phrase “is possible,” see, e.g., 
    id. §780-104(1)(i), as
    do counterpart statutes in other
    jurisdictions. See, e.g., 21 U.S.C. §812; KY. REV. STAT. §218A.050.
    8
    There is a fourteenth, “catchall,” classification defined as “[a]ny other synthetic
    chemical compound that is a cannabinoid receptor type 1 [i.e., CB1] agonist as
    demonstrated by binding studies and functional assays . . ..” 
    Id. §780-104(1)(vii)(14). (continued…)
                                          [J-124-2016] - 4
    Appellee filed an omnibus pre-trial motion which included a request for habeas
    corpus relief. See Commonwealth v. Hock, 
    556 Pa. 409
    , 414-15 & n.2, 
    728 A.2d 943
    ,
    945 & n.2 (1999) (noting that a pre-trial habeas petition tests whether the
    Commonwealth’s evidence is sufficient to make out a prima facie case of guilt).
    Appellee made several discreet assertions in support of his habeas request.
    First, he argued that both controlled-substance charges relating to dates after
    July 2, 2013 – i.e., the third delivery count and the possession count – should be
    dismissed because PB-22 is not a controlled substance under the revised Schedule I.
    Appellee reasoned that JWH-018 is a naphthoylindole, whereas PB-22 is an ester.9 As
    the two compounds fall into different structural classes, Appellee maintained, PB-22
    could not be an analogue of JWH-018 for purposes of the amended Section 780-
    104(1)(vii), given that that version expressly classifies prohibited synthetic cannabinoids
    by “specific chemical designation.” 35 P.S. §780-104(1)(vii) (2013). In this regard,
    Appellee proffered that the statutory phrase, “within the specific chemical designation,”
    (…continued)
    Appellee maintained before the county court that the word “analogues” in Section 780-
    104(1)(vii) did not apply to the catchall category in light of the qualifier, “within the
    specific chemical designation.” We will assume that is true for decisional purposes, as
    the Commonwealth does not presently argue that the catchall category is implicated.
    To the contrary, it concedes that no studies on the effects of PB-22 have been
    undertaken, see Brief for Appellant at 10, and hence, PB-22 has not been shown to be
    a CB1 agonist – i.e., that it binds to the body’s CB1 receptor and triggers a response.
    9
    Both chemical types have common components, but PB-22 has an “oxygen bridge”
    (an extra oxygen atom bridging two of the main components), and two extra nitrogen
    atoms, which gives it different properties. See N.T., Nov. 7, 2014, at 22-26 (reflecting
    Dr. Coyer’s description of the molecular structures of JWH-018 and PB-22). See
    generally United States v. Johnson, 
    2014 WL 7330936
    , at *5 (D. Nev. Dec. 19, 2014),
    reprinted in Brief for Appellant at app. 51a (showing two-dimensional diagrams of PB-22
    and JWH-018). The parties’ experts agreed that the chemicals are in different structural
    classes. See N.T., Nov. 7, 2014, at 47, 61.
    [J-124-2016] - 5
    
    id., should be
    understood to mean that the purported analogue must fall into the same
    structural classification. See Omnibus Pretrial Motion at 2-3. Notably, Appellee did not
    challenge the constitutional validity of the analogue provision in the revised statute.
    Appellee also advanced that the sole designer-drug charge should be dismissed
    for two reasons. First, he argued that the Commonwealth failed to offer any evidence
    that PB-22 has a chemical structure which is substantially similar to that of JWH-018,
    and that the Commonwealth’s own evidence, including Dr. Coyer’s lab reports, indicated
    that the physiological and toxicological properties of PB-22 are unknown – thus
    negating any claim that its effects are substantially similar to those of JWH-018. See
    Omnibus Pretrial Motion at 5. Alternatively, Appellee argued that the term “substantially
    similar” was void for vagueness as applied to the two compounds in question. See 
    id. Finally, Appellee
    argued that, in the relevant scientific field, there is no
    consensus as to the definition of an “analogue” of a chemical compound, nor is there a
    generally-accepted methodology for determining whether one molecule is an analogue
    of another. As applied to this case, Appellee reasoned that, if scientists cannot agree
    on whether PB-22 is an analogue of JWH-018, the average citizen could not be on
    notice of such a relationship between the two chemicals and, therefore, that PB-22 is an
    illegal drug. That being the case, Appellee continued, it would offend due process,
    under the void-for-vagueness doctrine, for the Commonwealth to prosecute him under
    subsection 780-113(a)(30) for delivering PB-22 as an alleged controlled substance in
    the pre-July 2, 2013, timeframe. See 
    id. at 3-4.10
    10
    Appellee also sought a hearing pursuant to Frye v. United States, 
    293 F. 1013
    (D.C.
    Cir. 1923), to test whether the method used by the Commonwealth’s expert to conclude
    PB-22 is an analogue of, and has a substantially-similar chemical structure to, JWH-
    018, is generally accepted in the relevant scientific field. Although the hearing on the
    habeas motion delved into those questions, it was not a Frye hearing, as it did not
    pertain to the admissibility of the prosecution’s evidence. The issue before the court
    (continued…)
    [J-124-2016] - 6
    To summarize, then, Appellee made three essential contentions: (1) that Section
    780-104(1)(vii) was vague as applied to PB-22 before July 2, 2013; (2) that PB-22 was
    not a prohibited substance under Section 780-104(1)(vii) after July 2, 2013; and (3) that
    the designer-drug provision, Section 780-113(a)(36), could not validly be applied to PB-
    22.   Because subsection (a)(36) predicates culpability in the disjunctive on a
    substantially similar effect or chemical structure, this latter argument had two subparts:
    (a) since PB-22’s effects were unknown, they could not possibly be proved to be
    substantially similar to those of JWH-018; and (b) either the Commonwealth did not
    satisfy its burden to demonstrate that PB-22 and JWH-018 shared a substantially similar
    chemical structure, or the term “substantially similar” was vague as applied to the
    structures of those two chemicals.
    The common pleas court held a hearing on the habeas motion at which Dr.
    Coyer testified as an expert for the Commonwealth and two expert witnesses testified
    on behalf of Appellee. Dr. Coyer opined, to a reasonable degree of scientific certainty,
    that PB-22 is an analogue of JWH-018. See N.T., Nov. 7, 2014, at 35. He conceded,
    (…continued)
    was whether the provisions of the Act under which Appellee was charged were
    inapplicable under the circumstances or unconstitutionally vague as applied. Further,
    the court never made a preliminary finding that the science involved was novel. See
    N.T., Nov. 7, 2014, at 45. See generally Commonwealth v. Puksar, 
    597 Pa. 240
    , 253,
    
    951 A.2d 267
    , 275 (2008) (observing that Frye only applies to “proffered expert
    testimony involving novel science” (internal quotation marks and citations omitted)).
    This is not entirely a formal distinction. The proponent of novel scientific evidence has
    the burden of establishing all prerequisites to admission, including conformance with
    Frye, see Grady v. Frito-Lay, Inc., 
    576 Pa. 546
    , 558, 
    839 A.2d 1038
    , 1045 (2003),
    whereas the party advancing a constitutional challenge to a statute bears the burden of
    demonstrating a constitutional violation. See Clifton v. Allegheny Cnty., 
    600 Pa. 662
    ,
    702, 
    969 A.2d 1197
    , 1221 (2009). Overall, however, the Commonwealth shoulders the
    burden to show evidentiary sufficiency for purposes of a pre-trial habeas motion. See
    Commonwealth v. Prosdocimo, 
    331 Pa. Super. 51
    , 52, 
    479 A.2d 1073
    , 1074 (1984).
    [J-124-2016] - 7
    however, that there was no definition of “analogue” in the relevant scientific field, but
    that he considered the term to mean a compound which “has a similar structure but may
    possess different properties.” 
    Id. at 36.
    In terms of methodology, Dr. Coyer indicated
    that he used a four-part process to arrive at this type of expert opinion: he visually
    compared two-dimensional diagrams of the molecules in question; he compared their
    potency or function; he reviewed his colleagues’ unpublished reports, anecdotal
    evidence, and peer-reviewed articles, if any; and he drew upon his experience
    conducting chemical analyses in his capacity as a forensic toxicologist. See 
    id. at 40-
    42. However, Dr. Coyer was unable to identify any peer-reviewed articles suggesting
    that his methodology was a generally-accepted means for determining whether one
    compound is an analogue of another.       Finally, he clarified that his method did not
    employ a comparison of three-dimensional molecular illustrations. See 
    id. at 51.
    Appellee’s first expert witness was John W. Huffman, PhD, an organic chemist
    and professor emeritus at Clemson University who had been active in the cannabinoid
    field for decades. Dr. Huffman, for whom JWH-018 is named, created the compound
    when conducting federally-funded research into how such chemicals interact with the
    body’s cannabinoid receptors. He agreed with Dr. Coyer that there was no scientific
    definition of “analogue” and that PB-22 and JWH-018 were in different structural
    classes. See 
    id. at 61,
    81-82. Therefore, Dr. Huffman opined that the two compounds
    were not analogues and did not have similar structures. See 
    id. at 90-91.
    Referring to
    a peer-reviewed scientific paper, Dr. Huffman also noted, consistent with Dr. Coyer’s lab
    reports, that scientists had no knowledge of PB-22’s pharmacological or toxicological
    effects, or of whether the two chemicals have similar effects. That being the case, he
    continued, there was no agreement in the scientific community on whether PB-22 could
    properly be classified as a synthetic cannabinoid, see 
    id. at 83-84,
    notwithstanding that
    [J-124-2016] - 8
    one team of chemists had labeled it as such “a few years ago.” 
    Id. at 84.
    Dr. Huffman
    stated that he had never heard of anyone else using Dr. Coyer’s four-part technique for
    discerning whether one molecule is an analogue of another. He testified that such
    methodology was not generally accepted in the scientific field, particularly as three-
    dimensional modeling, not two-dimensional diagraming, was the accepted standard for
    comparative analysis of molecular structures. See 
    id. at 76-77,
    81-82.
    Appellee also presented the expert testimony of Heather Harris, PhD, a forensic
    analytical chemist and chair of the Structure Subcommittee of the Advisory Committee
    for the Evaluation of Controlled Substance Analogues (“ACECSA”), a national scientific
    body. Dr. Harris explained that the mission of ACECSA – which also includes members
    of law enforcement agencies – is to develop methods for forensic chemists to use in
    discerning whether one chemical is an analogue of another. She testified that ACECSA
    had not yet developed such a methodology. See 
    id. at 96.
    Dr. Harris also discussed an
    entity funded by the federal Drug Enforcement Agency called the Scientific Working
    Group    for   the   Analysis   of   Seized   Drugs      (“SWGDRUG”),    which   publishes
    recommendations for chemists involved in testing controlled substances. She noted
    SWGDRUG includes an analogue subcommittee which had as yet been unable to
    devise a methodology for determining whether a particular chemical is an analogue of a
    controlled substance. See 
    id. at 97-98.
    Dr. Harris additionally related that she had
    recently reviewed the scientific literature. Based on that review, she opined that Dr.
    Coyer’s comparison methodology was not generally accepted in the scientific field. She
    added that she had been unable to locate any generally-accepted methodology. As
    well, Dr. Harris testified that there is also no commonly-accepted scientific definition of
    the phrase “substantially similar,” which she viewed to be a subjective term. Ultimately,
    [J-124-2016] - 9
    she rendered her own professional opinion, to a reasonable degree of scientific
    certainty, that PB-22 and JWH-018 are not substantially similar. See 
    id. at 102.
    The common pleas court granted Appellee’s habeas motion and dismissed all
    charges against him.11     In its Rule 1925(a) opinion, the court relied largely on the
    testimony of Drs. Hoffman and Harris. Based on such proofs, as well as portions of Dr.
    Coyer’s testimony, the court determined that the public at large could not have been on
    notice that PB-22 was prohibited as either an analogue of JWH-018 or a compound with
    a chemical structure or effect substantially similar to that of JWH-018. The court thus
    found the relevant portions of the Act unconstitutionally vague as applied to PB-22. As
    such, it concluded that the Commonwealth had failed to make out a prima facie case
    because it could not show that the products in question were prohibited substances
    under the Act. See Commonwealth v. Herman, No. CP-67-CR-2400-2014, slip op. at 8-
    9 (C.P. York May 28, 2015). See generally Commonwealth v. McBride, 
    528 Pa. 153
    ,
    157-58, 
    595 A.2d 589
    , 591 (1991) (observing that, to make out a prima facie case, the
    government must demonstrate a crime was committed, probably by the accused).12
    11
    Appellee had also been charged with criminal conspiracy and dealing in the proceeds
    of unlawful activities. See 18 Pa.C.S. §§903(a), 5111(a)(1). We need not discuss those
    counts separately as their viability depends on that of the drug charges at the center of
    this case.
    12
    The court also briefly discussed Frye and indicated that Dr. Coyer’s evidence was not
    generally accepted in the scientific community. See Herman, No. CP-67-CR-2400-
    2014, slip op. at 10-11. This aspect of the opinion can be read to suggest that the court,
    in retrospect, viewed the proceeding as a Frye hearing, at least in part. As explained,
    though, the court did not find preliminarily that the scientific evidence was novel, nor did
    it indicate the admissibility of Dr. Coyer’s testimony was in issue. See supra note 10.
    Separately, the court did not address Appellee’s statutory argument that PB-22 was
    legal under Act 40. As the court had already found “analogue” to be unconstitutionally
    vague – a question it could not avoid relative to charges based on conduct occurring in
    the pre-Act 40 timeframe – it may have seen no need to address that claim.
    [J-124-2016] - 10
    The county court’s decision is now on direct appeal to this Court.          See 42
    Pa.C.S. §722(7) (giving this Court exclusive appellate jurisdiction of common pleas
    court decisions ruling a statute unconstitutional).13 At the heart of that decision is the
    court’s holding that the Act is unconstitutionally vague as applied to PB-22.
    Presently, the Commonwealth argues that the common pleas court erred in
    granting relief based on a judicial finding that the terms “analogue” and “substantially
    similar” were unconstitutionally vague as applied. The Commonwealth maintains that
    the expert witnesses all confirmed that the two compounds, JWH-018 and PB-22, had
    structurally similar molecular components, albeit they differed regarding whether the two
    chemicals were sufficiently similar to meet statutory requirements.                In the
    Commonwealth’s view, whether they are sufficiently alike to be considered
    “substantially similar” or “analogues” is a question of fact for the jury to determine upon
    hearing expert testimony from both sides.14 In this regard the Commonwealth urges
    that statutory words should be understood according to their common usage, see Brief
    for Appellant at 16 (quoting 1 Pa.C.S. §1903(a)), and that, here, the dictionary defines
    “analogue” as “[o]ne of a group of chemical compounds similar in structure but different
    in composition,” 
    id. (quoting RANDOM
    HOUSE WEBSTER'S COLLEGE DICTIONARY 47 (2d ed.
    2001)) – a definition that juries can comprehend and apply.
    Finally, the Commonwealth points to three unpublished United States District
    Court decisions rejecting a void-for-vagueness claim in situations where the defendants
    13
    The Commonwealth initially appealed to the Superior Court. Upon recognizing the
    underlying constitutional basis for the common pleas court’s decision, the intermediate
    court transferred the matter here. See Commonwealth v. Herman, 
    143 A.3d 392
    , 394
    (Pa. Super. 2016); Pa.R.A.P. 751 (relating to the transfer of erroneously-filed cases).
    14
    The Commonwealth’s designer-drug argument rests solely on the premise that a jury
    could find that the two compounds have a substantially similar chemical structure, rather
    than substantially similar effects. See supra note 8.
    [J-124-2016] - 11
    were charged under the federal Analogue Act, and the chemicals at issue were PB-22
    and JWH-018, or some variant of them. See United States v. Hoyt, 
    2014 WL 5023093
    (W.D. Va. Oct. 8, 2014), reprinted in Brief for Appellant at app. 27a; United States v.
    Bays, 
    2014 WL 3764876
    (N.D. Tex. July 31, 2014), reprinted in Brief for Appellant at
    app. 34a; United States v. Johnson, 
    2014 WL 7330936
    (D. Nev. Dec. 19, 2014),
    reprinted in Brief for Appellant at app. 47a.15 It adds that a number of other jurisdictions
    have concluded that the terms “analogue” and “substantially similar” are not void for
    vagueness when applied to other controlled substances. See Brief for Appellant at 20-
    23 (citing cases). The Commonwealth maintains that these other decisions provide
    guidance and additionally militate in favor of reaching the same conclusion to maintain
    uniformity across jurisdictions.   See 
    id. at 18
    (quoting 1 Pa.C.S. §1927 (“Statutes
    uniform with those of other states shall be interpreted and construed to effect their
    general purpose to make uniform the laws of those states which enact them.”)).
    15
    The federal Analogue Act is a 1986 addition to the Controlled Substances Act, 21
    U.S.C. §§801-971 (the “Federal CSA”), which prescribes that controlled substance
    analogues “shall, to the extent intended for human consumption, be treated, for the
    purposes of any Federal law as a controlled substance in schedule I.” 
    Id. §813. The
    Federal CSA defines a “controlled substance analogue” generally as a substance
    whose chemical structure is substantially similar to that of a schedule I or II controlled
    substance, and either: (a) “has a stimulant, depressant, or hallucinogenic effect on the
    central nervous system that is substantially similar to or greater than the stimulant,
    depressant, or hallucinogenic effect on the central nervous system of a controlled
    substance in schedule I or II,” or (b) “with respect to a particular person, which such
    person represents or intends to have a stimulant, depressant, or hallucinogenic effect
    on the central nervous system that is substantially similar to or greater than the
    stimulant, depressant, or hallucinogenic effect on the central nervous system of a
    controlled substance in schedule I or II.” 
    Id. §802(32). See
    generally United States v.
    Turcotte, 
    405 F.3d 515
    , 522-23 (7th Cir. 2005) (construing the statute).
    [J-124-2016] - 12
    II. Analysis
    A. The void-for-vagueness doctrine
    The concept of unconstitutional vagueness arises from due process norms. See
    U.S. CONST. amends. V, XIV; Welch v. United States, ___ U.S. ___, ___, 
    136 S. Ct. 1257
    , 1261-62 (2016) (observing that the void-for-vagueness doctrine is grounded in
    the Fifth Amendment with regard to the federal government, and the Fourteenth
    Amendment with regard to the States).         It prevents the government from imposing
    sanctions under a criminal law that fails to give fair notice of the proscribed conduct.
    See Johnson v. United States, ___ U.S. ___, ___, 
    135 S. Ct. 2551
    , 2556 (2015) (citing
    Kolender v. Lawson, 
    461 U.S. 352
    , 357-58, 
    103 S. Ct. 1855
    , 1858 (1983)); see also
    Papachristou v. City of Jacksonville, 
    405 U.S. 156
    , 162, 
    92 S. Ct. 839
    , 843 (1972)
    (“Living under [the] rule of law entails various suppositions, one of which is that ‘[all
    persons] are entitled to be informed as to what the State commands or forbids.’”
    (quoting Lanzetta v. New Jersey, 
    306 U.S. 451
    , 453, 
    59 S. Ct. 618
    , 619 (1939) (second
    alteration in original))).     Relatedly, the doctrine safeguards against arbitrary or
    discriminatory enforcement by the government, see FCC v. Fox Television Stations,
    Inc., 
    567 U.S. 239
    , ___, 
    132 S. Ct. 2307
    , 2317 (2012), as well as jury verdicts
    “unfettered by any legally fixed standards as to what is prohibited by the statute.” State
    v. Golston, 
    67 So. 3d 452
    , 463 (La. 2011). Still, due process recognizes that because
    we are “[c]ondemned to the use of words, we can never expect mathematical certainty”
    in legislative draftsmanship. Grayned v. City of Rockford, 
    408 U.S. 104
    , 110, 
    92 S. Ct. 2294
    , 2300 (1972). Ultimately, the inquiry is whether the law “forbids or requires the
    doing of an act in terms so vague that [persons] of common intelligence must
    necessarily guess at its meaning and differ as to its application[.]” Connally v. Gen.
    Constr. Co., 
    269 U.S. 385
    , 391, 
    46 S. Ct. 126
    , 127 (1926).
    [J-124-2016] - 13
    Where, as here, a vagueness challenge does not involve First Amendment
    freedoms, it is “examined in the light of the facts of the case at hand,” United States v.
    Powell, 
    423 U.S. 87
    , 92, 
    96 S. Ct. 316
    , 319 (1975) (internal quotation marks and citation
    omitted), and “the statute is judged on an as-applied basis.” Maynard v. Cartwright, 
    486 U.S. 356
    , 361, 
    108 S. Ct. 1853
    , 1858 (1988); Commonwealth v. Heinbaugh, 
    467 Pa. 1
    ,
    5, 
    354 A.2d 244
    , 245 (1976). Thus, we consider the record developed in the common
    pleas court and evaluate whether Appellee met his burden to demonstrate that the
    statutory terms in question are unconstitutionally vague as applied to the chemicals
    JWH-018 and PB-22.       In doing so, we bear in mind that statutes enjoys a strong
    presumption of validity and will only be declared void if they clearly and plainly violate
    the Constitution, with all doubts resolved in favor of a finding of constitutionality. See
    Commonwealth v. Bullock, 
    590 Pa. 480
    , 487, 
    913 A.2d 207
    , 211-12 (2006).              See
    generally In re Adoption of E.M.A., 
    487 Pa. 152
    , 155, 
    409 A.2d 10
    , 11-12 (1979) (noting
    that this presumption pertains in an as-applied vagueness challenge), superseded by
    statute on other grounds, 23 Pa.C.S. §2701(7); In re Adoption of R.B.F., 
    569 Pa. 269
    ,
    281, 
    803 A.2d 1195
    , 1202 (2002). We defer to the common pleas court’s findings of
    fact that are supported by the record, but we review questions of law – including the
    Act’s constitutionality – de novo. See Commonwealth v. Davidson, 
    595 Pa. 1
    , 11, 
    938 A.2d 198
    , 203 (2007).
    B. The controlled-substance analogue counts prior to Act 40
    As most of the charges against Appellee involve the claim that PB-22 is a
    chemical analogue of JWH-018, and the bulk of the pre-trial hearing testimony related to
    the term “analogue,” we first question whether the Act’s use of the term prior to the Act
    [J-124-2016] - 14
    40 amendments was unconstitutionally vague as applied to those two chemicals.16 As
    an initial matter, although the federal Analogue Act defines “analogue” in terms of a
    substantially similar chemical structure, see 21 U.S.C. §802(32)(A)(i), and a number of
    our sister States have legislation containing a similar definition of a controlled substance
    analogue, see, e.g., CAL. HEALTH & SAFETY CODE §11401(b); COLO. REV. STAT. §18-18-
    102(6); 720 ILL. COMP. STAT. 570/401; KAN. STAT. §§65-4101(g), 21-5701(b); LA. REV.
    STAT. §40:961(8); OHIO REV. CODE §3719.01(HH); TEX. HEALTH & SAFETY CODE
    §§481.002(6), 481.102, the Pennsylvania enactment provides no such definition or any
    other express guidance. Additionally, the Act defines designer drugs in such terms and
    clarifies that designer drugs are not within the set of chemicals which constitute
    controlled substances.    See 35 P.S. §780-102.          Thus, although many jurisdictions
    appear to equate controlled substance analogues with a certain group of compounds
    whose chemical structure is substantially similar to that of the controlled substance in
    question, this type of equivalence is not reasonably supported by the express terms of
    the Act.
    Such a lack of guidance would not be especially problematic if an accepted
    meaning of the word “analogue” existed within the relevant scientific community, or if
    there was general acceptance that PB-22 is, in fact, an analogue of JWH-018.
    However, the expert testimony for both parties at the habeas hearing confirmed that
    there is no widely accepted definition of the term “analogue” as applied to these types of
    16
    If the common pleas court had found as a fact that PB-22 was not an analogue of
    JWH-018, we could potentially avoid this constitutional issue by deferring to that finding.
    However, the court made no such finding and, moreover, Dr. Coyer opined that PB-22
    was an analogue of JWH-018. See N.T., Nov. 7, 2014, at 35. That testimony must be
    accepted as true for the narrow purpose of ascertaining whether the Commonwealth
    made out a prima facie case. See Commonwealth v. MacPherson, 
    561 Pa. 571
    , 585,
    
    752 A.2d 384
    , 391 (2000). This, in turn, forecloses the possibility that we can affirm the
    court’s order based on an appellate finding that PB-22 is not an analogue of JWH-018.
    [J-124-2016] - 15
    organic molecules. See N.T., Nov. 7, 2014, at 34-35 (testimony of Dr. Coyer); 
    id. at 82
    (testimony of Dr. Huffman). The testimony also established that JWH-018 and PB-22
    are in different structural classes, see supra note 9, and Dr. Huffman testified that
    chemicals in different structural classes are not analogues of one another – and that,
    specifically, PB-22 is not an analogue of JWH-018. See 
    id. at 90-91.
    Dr. Huffman did
    clarify on cross-examination that the more particularized term “structural analogue” is
    sometimes used to refer to compounds that can be synthesized from a common parent
    molecule, and that the phrase can also refer to chemicals with the same basic
    molecular structure. See 
    id. at 88.
    And Dr. Coyer opined that PB-22 is an analogue of
    JWH-018 insofar as its structure is concerned. See 
    id. at 35-37.
    As to whether PB-22
    is a synthetic cannabinoid in terms of mimicking the effects of known cannabinoids,
    however, Dr. Coyer was only able to state that some “initial testing may have been
    done” to ascertain its effects as such, 
    id. at 37,
    and that in informal conversations some
    chemists group PB-22 together with JWH-018. See also 
    id. at 38
    (explaining that there
    was “a talk” focusing on whether a group of new compounds, including PB-22, were
    synthetic cannabinoids, but he did not wish to speak about that talk because it was only
    “a meeting”).
    Particularly in light of the admitted lack of scientific studies as to PB-22’s effects
    within the body, we find this type of evidence to be insufficient to establish that there is
    any agreement in the scientific community that PB-22 is a known synthetic cannabinoid.
    Moreover – and more to the point – it appears there is no scientifically accepted method
    for ascertaining whether PB-22 is an analogue of JWH-018. In this respect, Appellee’s
    second expert, Dr. Harris, was in a unique position to know whether, from a legal
    perspective, scientists are aware of any methodology to determine whether a compound
    under investigation can be considered an analogue of a controlled substance. She
    [J-124-2016] - 16
    belonged to ACECSA, a national scientific committee specially dedicated to discovering
    or fashioning such methods for law enforcement agencies to use. Dr. Harris testified
    that, as of the date of the hearing, ACECSA had not yet devised such a method. See
    
    id. at 96.
    She added that SWGDRUG’s analogue subcommittee had been similarly
    unable to formulate any such methodology, ultimately concluding that “it comes down to
    a subjective determination dependent not only upon what you are evaluating, but also
    the experience within [sic] the molecule itself.” 
    Id. at 97.
    Under these circumstances, we find resonance in the argument Appellee made
    in his habeas motion suggesting that scientists in the relevant field have not been able
    to agree on a method to determine analogue status and cannot agree on whether PB-
    22 is an analogue of JWH-018 – and if that is true of scientists, it is difficult to see how
    the average citizen can be on notice of such status. The court in United States v.
    Forbes, 
    806 F. Supp. 232
    (D. Colo. 1992), faced a similar situation with regard to
    alphaethyltryptamine (“AET”), which the government claimed was a controlled-
    substance analogue of the scheduled drugs dimethyltryptamine (“DMT”) and
    diethyltryptamine (“DET”). After hearing pre-trial expert testimony from both sides not
    unlike that adduced in the present case, the court stated that “[t]he scientific community
    cannot even agree on a methodology to use” to determine analogue status under the
    federal statute. 
    Id. at 237
    (emphasis added). Thus, the court concluded, “a defendant
    cannot determine [such status] in advance of his contemplated conduct[.]” 
    Id. The same
    observations apply to the question of whether PB-22 is an analogue of
    JWH-018 under the Act (at least prior to its Act 40 revisions). The average citizen
    would necessarily have to “guess at” PB-22’s status and “differ as to [the] application” of
    the analogue prohibition contained in Section 780-104(1)(vii). 
    Connally, 269 U.S. at 391
    , 46 S. Ct. at 127. Consequently, we agree with Appellee and the common pleas
    [J-124-2016] - 17
    court that the pre-Act 40 statute was unconstitutionally vague as applied to PB-22 and
    JWH-018.17
    Nor are we persuaded by the Commonwealth’s assertion that the vagueness
    question can be dispensed with by characterizing as a jury question whether PB-22 is
    an analogue of JWH-018. We need not address whether PB-22’s analogue status
    could theoretically be a question for the fact-finder if the Act were constitutional. The
    point here is that the Commonwealth’s argument starts from the assumption that the act
    is not vague as applied to PB-22, which is the very issue before this Court.
    We also differ with the government’s suggestion that because the Act is part of a
    uniform law, Section 1927 of the Statutory Construction Act directs that it be construed
    uniformly with similar laws of other jurisdictions. Although the Act is based on the
    Uniform Controlled Substances Act of 1970, see 35 P.S. Ch. 6, Table, Section 1927
    does not necessarily apply.    For one thing, neither the Act’s title nor its provisions
    suggest an intention to conform Pennsylvania’s drug regulations to those of other
    jurisdictions. See Allegheny Cnty. v. Rendell, 
    580 Pa. 149
    , 166 n.6, 
    860 A.2d 10
    , 21 n.6
    (2004) (explaining that Section 1927 only pertains where the substantive language of
    the enactment indicates that it is “part of a uniform enactment among several states”).
    Just as important, many states have now adopted a later version of the uniform act
    which was revised to include a definition of “controlled substance analog” which is
    expressed in terms of substantial similarity to a controlled substance, see UNIF.
    17
    We pause to emphasize that the problem is made acute by the specific wording of the
    Act. Unlike legislatures elsewhere, the General Assembly has placed the substantial-
    similarity test – which would ordinarily comprise the most probable standard for
    determining analogue status – within the designer drug provision, and has clarified that
    designer drugs and controlled substances (including analogues) are mutually exclusive
    categories. See supra note 5. It has done so, moreover, without delineating any
    substitute standard for determining what constitutes an analogue.
    [J-124-2016] - 18
    CONTROLLED SUBSTANCES ACT §101(3) (1990) – in other words, which tracks the Act’s
    definition of a designer drug. See supra note 17. Other state decisions, such as those
    highlighted by the Commonwealth, are based on the 1990 definition and, as such, do
    not support the Commonwealth’s uniformity argument relative to the Act’s “analogue”
    provision. See, e.g., People v. Lucero, 
    381 P.3d 436
    , 440 (Colo. App. 2016); State v.
    Barnes, 
    64 P.3d 405
    , 408 (Kan. 2003); State v. Smith, 
    525 N.W.2d 264
    , 267 (Wis.
    1995). See generally Richard L. Braun, Uniform Controlled Substances Act of 1990, 13
    CAMPBELL L. REV. 365, 367 (1991) (confirming that the 1990 uniform act’s controlled-
    substance analogue provision was drafted to encompass designer drugs).
    Finally, and as noted, the Commonwealth highlights several federal decisions,
    including three United States District Court opinions, which hold that, under the federal
    Analogue Act, PB-22 is an analogue of JWH-018. However, those disputes do not
    purport to address the salient issue before this Court because, as with the 1990 version
    of the uniform act, they relate to the federal Analogue Act’s definition of a “controlled
    substance analogue” as a chemical having a substantially similar chemical structure to
    a scheduled drug. See 21 U.S.C. §802(32)(A)(i). Their present relevance, if any, is
    thus limited to the designer-drug charge (discussed below) as the Act defines designer
    drug in similar terms, but it provides no definition of “analogue.”
    Accordingly, we hold that in the pre-Act 40 timeframe the analogue provision was
    unconstitutionally vague as applied to PB-22 as an alleged analogue of JWH-018. That
    being the case, the common pleas court acted properly in dismissing the charges
    lodged against Appellee based on the April and May 2013 undercover purchases.
    C. The controlled-substance analogue counts after Act 40
    Appellee was also charged with delivery of a controlled substance (PB-22) based
    on the July 11, 2013, undercover purchase, and with a possession with intent to deliver
    [J-124-2016] - 19
    a controlled substance based on the July 15, 2013, packet seizures. Both of those
    charges were lodged pursuant to the Act as amended by Act 40.                 As explained,
    Appellee never claimed in his habeas motion that the amended statute’s use of the term
    “analogue” was unconstitutionally vague as applied. Rather, he maintained that PB-22
    was not a prohibited substance inasmuch as it was excluded from Schedule I due to the
    statute’s use of specific chemical designations. He asserted, in this respect, that PB-22
    is not in any of the listed designations, and specifically, is not the same chemical
    designation as JWH-018. See N.T., Nov. 7, 2014, at 32-33, 108-10 (reflecting defense
    counsel’s repetition at the habeas hearing of this non-constitutional, interpretive basis
    for challenging the post-July 2 controlled-substance charges). On appeal, Appellee
    continues to forward this same argument as his only contention with regard to these
    charges. See Brief for Appellee at 4-8.18
    As described above, the statutory description of Schedule I cannabinoids as
    stated in the revised Act only prohibited certain chemicals and their analogues within
    thirteen enumerated chemical designations – the relevant one being naphthoylindoles
    inasmuch as it includes JWH-018, see 35 P.S. §780-104(1)(vii)(2)(B) (2013) – and a
    “catchall” category of CB1 agonists, which is not presently relevant. See supra note 8.
    The prosecution’s expert confirmed that PB-22 is in a different chemical classification
    than JWH-018, and that it falls within a class of compounds known as indole carboxylic
    acids rather than naphthoylindoles. See N.T., Nov. 7, 2014, at 47. This has now been
    confirmed by the General Assembly in its most recent revision to the Act, see Act of
    18
    The common pleas court did not speak to this issue in its Rule 1925 opinion. Instead,
    it held that the term “analogue” was vague as applied without distinguishing between
    the pre- and post-amendment versions of the statute. Additionally, the Commonwealth
    does not address the claim in its brief, opting instead to limit its advocacy to the position
    that the terms “analogue” and “substantially similar” should not be deemed
    unconstitutionally vague.
    [J-124-2016] - 20
    June 8, 2016, P.L. 258, No. 37 (“Act 37”), in which the legislative body named PB-22 as
    a scheduled controlled substance under that very chemical designation. See 35 P.S.
    §780-104(1)(vii)(2.2) (2016) (listing PB-22 as one of a group of Schedule I controlled
    substances within the chemical designation “[i]ndole carboxylic acids”).
    Accordingly, the Commonwealth failed to identify a valid statutory basis on which
    Appellee could be charged with delivery of a controlled substance, or possession with
    intent to deliver a controlled substance, based his conduct after July 2, 2013. We
    therefore affirm the common pleas court’s dismissal of the relevant counts against
    Appellee, although we disagree with its analysis insofar as it suggested that the post-
    amendment Act’s use of “analogue” is unconstitutionally vague. 19 See Commonwealth
    v. Flanagan, 
    578 Pa. 587
    , 611, 
    854 A.2d 489
    , 503 (2004) (explaining that “this Court
    has the ability to affirm a valid judgment or order for any reason appearing as of
    record”). By reaching our holding on these grounds, we not only resolve Appellee’s
    claim on the terms in which he has framed it, we also “adhere to the sound tenet of
    jurisprudence that courts should avoid constitutional issues when the issue at hand may
    be decided upon other grounds.” In re Fiori, 
    543 Pa. 592
    , 600, 
    673 A.2d 905
    , 909
    (1996) (citing Rescue Army v. Mun. Court, 
    331 U.S. 549
    , 568-69, 
    67 S. Ct. 1409
    , 1419-
    20 (1947)); accord Threlkeld v. State, 
    558 S.W.2d 472
    , 474 (Tex. Crim. App. 1977)
    (“This Court will not pass on the [constitutional] validity of any part of the Controlled
    Substances Act which is not shown to have been violated[.]” (citation omitted)).
    D. The designer-drug count and the “substantially similar” descriptor
    Finally, Appellee was charged with a single count of possession with intent to
    distribute, or possession, of a designer drug. To review, the Act prohibits the “knowing
    19
    That issue will have to await another dispute where its resolution is material to the
    outcome of the case.
    [J-124-2016] - 21
    or intentional . . . possession with intent to distribute, or possession[,] of a designer
    drug,” 35 P.S. §780-113(a)(36); see supra note 3, which is defined in relevant part as “a
    substance other than a controlled substance that is intended for human consumption
    and that . . . has a chemical structure substantially similar to that of a controlled
    substance in Schedules I, II or III . . . or that produces an effect substantially similar to
    that of a controlled substance in Schedules I, II or III.” 
    Id. §780-102.20 Before
    the common pleas court, Appellee claimed an entitlement to habeas relief
    on this charge solely on the basis that the “substantially similar” descriptor was vague.
    The common pleas court agreed with Appellee and expressed its rationale in succinct
    terms. The court found that “experts have been unable to reach an agreement on a
    method for analyzing and determining the similarities between the chemical structures .
    . . of PB-22 and JWH-018.” Herman, No. CP-67-CR-2400-2014, slip op. at 9.                  It
    concluded that “[t]his disagreement renders the designer drug statute unconstitutionally
    vague.” 
    Id. In his
    appellate brief, Appellee only argues that that the effects of PB-22
    are unknown, see Brief for Appellee at 8-9, which is not in dispute. Appellee appears to
    overlook that, unlike the federal CSA, the Act’s definition of designer drug is phrased in
    the disjunctive. Thus, he may still be liable under Section 780-113(a)(36) if PB-22’s
    chemical structure is substantially similar to that of JWH-018.        The salient issue is
    whether that term – “substantially similar” – is vague as applied to the chemical
    structures of PB-22 and JWH-018.
    Although the bulk of the testimony at the habeas hearing focused on the term
    “analogue,” the county court’s finding that experts disagree on a method for determining
    20
    As of June 2016, PB-22 is not a designer drug because Act 37 made it a scheduled
    controlled substance. See 35 P.S. §780-104(1)(vii)(2.2) (2016). For present purposes,
    we apply the Act as it existed on July 15, 2013, when the PB-22 packets were seized.
    [J-124-2016] - 22
    substantial similarity as between chemical structures is supported by the record.21
    Initially, the experts agreed that, although the overall molecular structures of the two
    chemicals were different, they had similar components. See N.T., Nov. 7, 2014, at 25,
    38-39 (testimony of Dr. Coyer), 85-86 (testimony of Dr. Huffman).        Dr. Coyer went
    further and opined that their components were “very similar,” 
    id. at 25,
    and his testimony
    as a whole was acknowledged by Appellee as subsuming an expression that the overall
    molecular structures were substantially similar. See 
    id. at 99.
    The defense experts
    disagreed. Dr. Huffman opined that the two molecules did not have “similar structures,”
    
    id. at 91;
    see also 
    id. at 86
    (“[T]he total structures are different.”), and Dr. Harris
    indicated that they were not “structurally similar as a whole.”      
    Id. at 99.
      Just as
    important, both defense experts highlighted the importance of three-dimensional
    comparisons in reaching a conclusion on structural similarity.       See 
    id. at 77
    (Dr.
    Huffman), 100 (Dr. Harris).    Dr. Harris continued by expressing that “substantially
    similar” is not a scientific term and “substantial” means different things to different
    people. 
    Id. at 101.
    We have difficulty, however, with the common pleas court’s ultimate holding.
    While the term “analogue” may be somewhat nebulous (particularly in a scientific
    setting), the concept of similarity is well known to persons of ordinary intelligence, and
    we see no reason why such individuals would have difficulty applying it to evidence of
    the molecular structures of PB-22 and JWH-018. Accord United States v. McKinney, 79
    21
    Dr. Harris’ testimony regarding efforts at the federal level to discover a methodology
    for ascertaining whether one chemical is an analogue of another can be construed as
    touching on the question of substantial similarity in light of the federal Analogue Act’s
    use of that term in its definition of a controlled substance analogue. However, it cannot
    be seen as addressing only chemical-structure similarity, since the federal definition
    also includes a requirement that the effects on the central nervous system be
    substantially similar.
    [J-124-2016] - 
    23 F.3d 105
    , 108 (8th Cir. 1996) (rejecting a claim that the federal Analogue Act’s use of
    “substantially similar” was vague, and explaining that “a reasonable layperson could . . .
    have examined a chemical chart and intelligently decided for himself or herself, by
    comparing their chemical diagrams, whether the chemical structures of the two
    substances were substantially similar”), judgment vacated on other grounds, 
    520 U.S. 1226
    , 
    117 S. Ct. 1816
    (1997). The fact that the parties’ experts disagreed on the
    ultimate issue of substantial similarity in this case is not dispositive, particularly given
    the obvious visual similarities in the two-dimensional diagrams of the molecules.22
    Accord United States v. Klecker, 
    348 F.3d 69
    , 72 (4th Cir. 2003) (where diagrams of the
    two molecules at issue revealed “considerable similarities,” holding that the
    “substantially similar” standard was not vague as applied notwithstanding that the
    parties’ experts disagreed on the question of whether they were substantially similar).
    The “substantial” qualifier speaks to the degree of similarity needed to bring a
    substance within the designer drug prohibition. Still, “substantial similarity” is not a
    scientific concept, accord Controlled Substance Analogues 4, and although that
    adjective may be qualitative, the Supreme Court has stressed that it does not “doubt the
    22
    The statute does not articulate a particular manner of proof. As such, it does not
    require that substantial similarity be proved by two-dimensional diagrams, nor does it
    preclude proof by three-dimensional diagrams, models, holograms, or indeed any other
    evidence pertinent to the issue. In this regard, some commentators have expressed
    that two-dimensional stick-and-letter chemical structure diagrams are an inferior type of
    evidence, as they omit relevant information such as atomic mass and the three-
    dimensional structure. See Paul Anacker & Edward J. Imwinkelried, The Confusing
    World of the Controlled Substance Analogue (CSA) Criminal Defense, 42:6 CRIM. L.
    BULL. ART. 4 (2006) (hereinafter, “Controlled Substance Analogues”); cf. Bays, 
    2014 WL 3764876
    , at *8 (referring with approval to expert testimony suggesting that two-
    dimensional chemical models are useful for determining core structure, whereas three-
    dimensional models are helpful in identifying attached functional groups and seeing how
    they are similar). Whether evidentiary sufficiency to prove guilt can be predicated solely
    on comparing two-dimensional diagrams is not an issue presently before the Court.
    [J-124-2016] - 24
    constitutionality of laws that call for the application of a qualitative standard such as
    ‘substantial risk’ to real-world conduct” – noting, further, that “‘the law is full of instances
    where a man’s fate depends on his estimating rightly . . . some matter of degree.’”
    Johnson, ___ U.S. at ___, 135 S. Ct. at 2561 (quoting Nash v. United States, 
    229 U.S. 373
    , 377, 
    33 S. Ct. 780
    , 781 (1913)); see 21 AM. JUR. 2D §17 (2017).
    We also observe that the vast weight of authority from other jurisdictions
    supports the conclusion that “substantially similar” is not a vague term per se when
    used in comparing two chemical compounds. The federal circuit courts which have
    examined this question have generally found that use of the “substantially similar”
    phraseology in the controlled substance arena does not suffer from unconstitutional
    vagueness.23 This view is also held by most appellate courts in other states.24 As
    applied specifically to PB-22 and JWH-018, moreover, Appellee has not drawn our
    attention to any court in any jurisdiction which has held that the substantially-similar
    descriptor is unconstitutionally vague; as noted above, the Commonwealth has included
    in its appendix three United States District Court decisions which have held that the
    federal Analogue Act – which, in relevant part, uses the same substantial-similarity
    standard as the designer drug provision presently under challenge – is not
    unconstitutionally vague as applied to these chemicals.
    23
    See 
    Turcotte, 405 F.3d at 533
    ; United States v. Ansaldi, 
    372 F.3d 118
    , 124 (2d Cir.
    2004); 
    Klecker, 348 F.3d at 72
    ; United States v. Granberry, 
    916 F.2d 1008
    , 1010 (5th
    Cir. 1990); United States v. Orchard, 
    332 F.3d 1133
    , 1138 (8th Cir. 2003); United States
    v. Fisher, 
    289 F.3d 1329
    , 1339 (11th Cir. 2002).
    24
    See People v. Silver, 
    281 Cal. Rptr. 354
    , 357 (Cal. Ct. App. 1991); State v. Alley, 
    318 P.3d 962
    , 973 (Idaho Ct. App. 2014); abrogated on other grounds by State v. McKean,
    
    356 P.3d 368
    (Idaho 2015); Hooper v. State, 
    106 S.W.3d 270
    , 277 (Tex. App. 2003);
    State v. Srack, 
    314 P.3d 890
    , 897 (Kan. Ct. App. 2013); State v. Beaudette, 
    97 So. 3d 600
    , 603-604 (La. App. 2012); State v. Shalash, 
    13 N.E.3d 1202
    , 1209 (Ohio Ct. App.
    2014).
    [J-124-2016] - 25
    Additionally, unlike the controlled-substance analogue offense, the designer drug
    provision has an express culpability prerequisite whereby a defendant can only be
    convicted if the government proves he acted knowingly or intentionally. See 35 P.S.
    §780-113(a)(36).     Scienter requirements of this nature help alleviate vagueness
    concerns, both with regard to the adequacy of notice of the proscribed conduct, see
    Village of Hoffman Estates v. Flipside, Hoffman Estates, Inc., 
    455 U.S. 489
    , 499, 102 S.
    Ct. 1186, 1193 (1982), and as a means of limiting prosecutorial discretion, see
    McFadden v. United States, ___ U.S. ___, ___, 
    135 S. Ct. 2298
    , 2307 (2015). The
    McFadden Court, which dealt with the federal Analogue Act, interpreted the scienter
    mandate as to controlled-substance analogues as meaning that the government must
    show that the defendant either knew that the substance was a controlled-substance
    analogue regardless of his knowledge of its identity, or knew that it satisfied the specific
    statutory prerequisites making it a controlled substance analogue. Those prerequisites
    include a substantially similar chemical structure to that of a scheduled controlled
    substance. See id. at ___, 135 S. Ct. at 2305 (quoting 21 U.S.C. §802(32)(A)). The
    Court concluded: “A defendant who possesses a substance with knowledge of those
    features knows all of the facts that make his conduct illegal[.]” Id.; see also Hoffman
    
    Estates, 455 U.S. at 499
    & 
    n.14, 102 S. Ct. at 1193
    & n.14 (reciting that the Supreme
    Court “has recognized that a scienter requirement may mitigate a law’s vagueness,
    especially with respect to the adequacy of notice to the complainant that his conduct is
    proscribed,” and citing cases); Boyce Motor Lines, Inc. v. United States, 
    342 U.S. 337
    ,
    342, 
    72 S. Ct. 329
    , 331-32 (1952) (indicating that a “knowingly” mens rea requirement
    “does much to destroy any force in the argument” that enforcement of the regulation in
    question would violate due process on vagueness grounds); United States v. Novak,
    
    841 F.3d 721
    , 728-29 (7th Cir. 2016) (summarizing the McFadden scienter analysis,
    [J-124-2016] - 26
    including the mandate that the government prove the accused knew the chemical
    structure was substantially similar to that of a scheduled controlled substance); cf.
    Tiplick v. State, 
    43 N.E.3d 1259
    , 1265 (Ind. 2015) (relying on an express scienter
    requirement in rejecting a vagueness challenge to a counterfeit-controlled-substance
    statute).
    There is no issue of statutory construction presently before this Court relating to
    the scope of the scienter requirement contained in Section 780-113(a)(36).
    Nevertheless, the Supreme Court’s analysis in McFadden bears upon the vagueness
    issue in the following way. Under the canon of constitutional avoidance, if a statute is
    susceptible of two reasonable constructions, one of which would raise constitutional
    difficulties and the other of which would not, we adopt the latter construction. See MCI
    WorldCom, Inc. v. PUC, 
    577 Pa. 294
    , 311, 
    844 A.2d 1239
    , 1249 (2004). Although the
    designer drug provision does not expressly state that, to be culpable, the defendant
    must know that the chemical he possesses has a molecular structure substantially
    similar to that of a scheduled drug, a narrow construction along those lines would be
    reasonable. See 18 Pa.C.S. §302(d) (providing generally that where the law prescribes
    a particular level of scienter, it applies to all elements of the offense in question); see
    also 
    id. §107(a) (specifying
    that Title 18’s preliminary provisions – including Section 302
    – apply to offenses defined in any statute). If a broader interpretation of the statute
    would render it vague as applied, the court would be obligated to adopt the narrower
    construction delineated above because, under McFadden, such a construction would
    alleviate vagueness concerns.
    Dissenting from the above, Justice Wecht initially suggests that an offense based
    on a substantial similarity of chemical structures fails to give adequate notice of the
    prohibited conduct as required by due process, because most citizens are not organic
    [J-124-2016] - 27
    chemists and the substances they purchase ordinarily are not accompanied by
    chemistry books or comparative chemical-structure diagrams.          See Concurring and
    Dissenting Opinion, slip op. at 3-7.
    While we certainly understand the concern, we are not convinced that an
    ordinary citizen’s lack of expertise in organic chemistry constitutes a viable basis to
    conclude that the statute is unconstitutionally vague. If it were, much of the Act would
    be invalid because many drugs appearing in the schedules are listed by their chemical
    formulae or technical designations.       See 35 P.S. §780-104 (listing such scheduled
    drugs as “N-ethyl-3-piperidyl benzilate,” “Delta-6 cis or trans tetrahydrocannabinol and
    their optical isomers,” and “2-(4-Chloro-2,5-dimethoxyphenyl)ethanamine (2C-C)”). A
    large part of the federal Controlled Substances Act would likewise fall. See 21 U.S.C.
    §812 (enumerating many controlled substances by chemical formulae). See generally
    United States v. Niemoeller, 
    2003 WL 1563863
    , at *4 (S.D. Ind. Jan. 24, 2013)
    (observing that “it takes a chemist to understand many of the compounds on schedule I
    under the Controlled Substances Act”). More generally, any offense which is predicated
    on an act or circumstance, the understanding of which involves specialized knowledge,
    would be at risk of invalidation under the vagueness doctrine.
    That doctrine has not developed so strictly as to impose a blanket prohibition
    along these lines, and we believe it would be misguided to invalidate substantial
    portions of our controlled-substance legislation on the basis that compounds subject to
    regulation or criminalization are described by reference to technical formulae
    unintelligible to the general public. Accord, e.g., State v. Heinrichs, 
    845 N.W.2d 450
    ,
    455 (Iowa Ct. App. 2013) (“[W]e decline to find the schedule of controlled substances is
    constitutionally defective because it uses scientific terms that are obscure to persons of
    ordinary intelligence lacking in specialized knowledge. ‘The use of scientific or technical
    [J-124-2016] - 28
    terminology or terms of art common in a regulated field does not automatically render a
    statute unconstitutionally vague.’” (quoting United States v. Caseer, 
    399 F.3d 828
    , 836-
    37 (6th Cir. 2005))). As one federal court noted more generally:
    When dealing with legislation on complex or technical matters – whether it
    concerns intricate corporate tax issues, the details of electronic securities
    transactions, or international trade in “dual use” technologies – Congress
    can expect a person who wishes to engage in the activity to acquire the
    necessary specialized knowledge to conform the person’s conduct to law.
    Similarly, when dealing with the distribution of organic chemical
    compounds for human consumption and with intended or hoped-for
    central nervous system effects, Congress could reasonably expect and
    require persons engaged in that activity to possess or obtain the
    specialized knowledge needed to conform their conduct to law.
    Niemoeller, 
    2003 WL 1563863
    , at *4; accord State v. Shalash, 
    13 N.E.3d 1202
    , 1210
    (Ohio Ct. App. 2014). In our view the above proceeds from a reasonable conception of
    the scope of discretion the legislative branch retains when it seeks to regulate activity
    that is potentially harmful to the public, and such activity can only be described using
    technical terminology understandable to individuals with specialized training.
    As discussed, moreover, an available interpretation of the designer drug statute
    incorporates a mens rea whereby defendants are only criminally liable if they act
    knowingly or intentionally with regard to all elements – including, for purposes of the
    present as-applied challenge, the alleged circumstance that PB-22’s chemical structure
    is substantially similar to that of JWH-018. This limitation helps ensure the statute does
    not become a trap for unwitting members of the public who have no expertise in organic
    chemistry. Instead, the statute is quite reasonably aimed at those who traffic in novel
    compounds which are essentially the same as scheduled controlled substances but
    contain minor differences designed to evade the statutory schedules. The General
    Assembly can “reasonably expect and require persons engaged in that activity to
    [J-124-2016] - 29
    possess or obtain the specialized knowledge needed to conform their conduct to law.”
    Niemoeller, 
    2003 WL 1563863
    , at *4.
    In a separate line of attack, Justice Wecht acknowledges the Supreme Court’s
    recent guidance in McFadden, as well as Colautti v. Franklin, 
    439 U.S. 379
    , 
    99 S. Ct. 675
    (1979), where a statute’s lack of a scienter requirement contributed to the Supreme
    Court’s finding that it was vague.    See 
    id. at 401,
    99 S. Ct. at 688.      Further, he
    recognizes that the Supreme Court has issued other decisions containing language
    similar to McFadden’s, indicating that scienter requirements mitigate, alleviate, or
    ameliorate vagueness concerns. See Concurring and Dissenting Opinion, slip op. at
    11-12 (citing cases). He also highlights a decision of this Court stating that “vagueness
    challenges fail when a statute has a specific intent requirement because a defendant
    cannot complain he did not understand the crime . . ..”          
    Id. at 12
    n.5 (quoting
    Commonwealth v. Hendrickson, 
    555 Pa. 277
    , 284, 
    724 A.2d 315
    , 319 (1999)).
    Nevertheless, Justice Wecht offers that the concept that a scienter prerequisite can help
    alleviate vagueness difficulties has been criticized by commentators, and that it is in
    tension with the maxim that ignorance of the law is not an excuse. See 
    id. at 12.
    Because the void-for-vagueness doctrine is grounded on federal due process
    norms, we believe the Supreme Court’s pronouncements are particularly germane to
    the resolution of the matter before us, notwithstanding the thoughtful contributions of
    learned commentators. As far back as 1979, the Supreme Court stated it “ha[d] long
    recognized that the constitutionality of a vague statutory standard is closely related to
    whether that standard incorporates a requirement of mens rea.” 
    Colautti, 439 U.S. at 395
    , 99 S. Ct. at 685. McFadden, in particular, is highly relevant since it dealt with a
    federal statute prohibiting knowing or intentional conduct – including possession with
    intent to distribute – relative to a controlled-substance analogue which, under the
    [J-124-2016] - 30
    federal system, is defined using the same substantially-similar-chemical-structure
    phraseology as Pennsylvania’s designer drug statute.           See 21 U.S.C. §§802(32)(A)
    (defining “controlled substance analogue” in terms of a chemical structure “which is
    substantially similar to the chemical structure of a controlled substance in schedule I or
    schedule II”), 841(a) (reflecting an express “knowingly or intentionally” mens rea);
    accord McFadden, ___ U.S. at ___ 
    n.2, 135 S. Ct. at 2305
    n.2 (reflecting that the
    government had to prove, inter alia, that the substance in question was “substantially
    similar in chemical structure to a controlled substance”).25
    Further, if the law being enforced only prohibits knowing or intentional conduct,
    any ignorance by a defendant which could defeat culpability would not be offered as an
    excuse.   See generally 18 Pa.C.S. §302(h).        It would be advanced as a basis to
    conclude that the Commonwealth failed to prove an element of the offense. Thus, any
    perceived tension with the legal maxim involving ignorance of the law is illusory. See,
    e.g., United States v. Int’l Minerals & Chem. Corp., 
    402 U.S. 558
    , 561-62, 
    91 S. Ct. 1697
    , 1700 (1971); Staples v. United States, 
    511 U.S. 600
    , 622 n.3, 
    114 S. Ct. 1793
    ,
    1805 n.3 (1994) (Ginsburg, J., concurring) (“The mens rea presumption requires
    knowledge only of the facts that make the defendant’s conduct illegal, lest it conflict with
    the related presumption . . . that . . . ignorance of the law . . . is no defense . . ..”
    (emphasis added)); United States v. Elias, 
    1999 WL 1204529
    , at *1 (D. Idaho Apr. 20,
    1999) (explaining that Staples and two other Supreme Court decisions “have not altered
    the traditional rule that ignorance of the law is no excuse, but have only stated that
    knowledge is required where the statute specifically imposes that type of requirement”);
    cf. Winget v. Rockwood, 
    69 F.2d 326
    , 332 (8th Cir. 1934) (in a civil setting,
    25
    Although 21 U.S.C. §841(a) facially applies to controlled substances, under the
    federal Analogue Act the term subsumes controlled substance analogues, see 21
    U.S.C. §813, the very category of chemicals at issue in McFadden.
    [J-124-2016] - 31
    distinguishing ignorance of the law from ignorance of certain facts); Ciesielski v.
    Prudential Ins. Co. of Am., 
    416 Pa. 146
    , 148, 
    205 A.2d 42
    , 43 (1964) (same).26
    Finally, we differ with any suggestion that we are treating the analogue provision
    and the designer drug statute in a logically inconsistent fashion. See Concurring and
    Dissenting Opinion, slip op. at 14-15 (Wecht, J.). Although a chemical analogue of a
    controlled substance would most naturally be understood as a molecule with a
    substantially similar chemical structure, as noted above the General Assembly has
    precluded that meaning by specifying that analogues and designer drugs are mutually
    exclusive categories – and has done so without providing any substitute standard for
    understanding what it intended to signify by the word “analogue.” See supra note 17.
    In summary, then, the common pleas court did not account for the difference
    between the concepts of analogue and substantial similarity, the latter of which is more
    readily apprehensible to the lay citizen in the context of comparing chemical structures;
    nor did it recognize that, unlike the controlled-substance provision, the designer drug
    provision includes a narrowing scienter specification.         Moreover, like the federal
    appellate court in Klecker, we find in this case that there are “considerable similarities”
    as between the two molecules based on their two-dimensional diagrams. 
    Klecker, 348 F.3d at 72
    ; see Johnson, 
    2014 WL 7330936
    , at *5 (concluding that “the readily apparent
    similarities between the chemical structures of 5F-PB-22 [a variant of PB-22] and the
    scheduled substances JWH-018 and AM-2201 [as reflected in two-dimensional
    diagrams], are enough to put a reasonable person on notice that 5F-PB-22 and JWH-
    018 are substantially similar”).
    26
    We note parenthetically that ignorance of the law can constitute a basis to escape
    liability if the applicable legislation specifies that, to be guilty, the defendant must have
    intended to violate the law. See, e.g., Ratzlaf v. United States, 
    510 U.S. 135
    , 149, 
    114 S. Ct. 655
    , 663 (1994).
    [J-124-2016] - 32
    In light of the foregoing, we conclude that predicating criminal liability on a jury
    determination – perhaps assisted by expert evidence – as to whether JWH-018 and PB-
    22 have substantially similar chemical structures does not give rise to a circumstance in
    which the average citizen must necessarily guess at the types of behavior that are
    proscribed by Section 780-113(a)(36).      For the same reasons – particularly those
    relating to the scienter provision – the discretion of government agents is adequately
    circumscribed to guard against arbitrary or discriminatory prosecutions. That being the
    case, this provision withstands the present void-for-vagueness challenge.27
    27
    Appellee claims that the Commonwealth waived the issue of whether PB-22 has
    substantially similar effects to those of JWH-018 by not including a claim along these
    lines in its Rule 1925(b) statement of matters complained of on appeal. See Brief for
    Appellee at 8-9. As previously noted, that question is not presently in dispute.
    To the extent Appellee’s brief may be understood as asserting waiver more generally in
    regard to the constitutionality of the designer drug charge, it should be noted that the
    order appealed from, issued on February 10, 2015, provided no explanation for its
    dismissal of all charges. In addition, by order dated March 13, 2015, the court directed
    the Commonwealth to file its Rule 1925(b) statement within 21 days, or no later than
    April 3, 2015. Notably, the court did not issue its opinion until May 28, 2015, long after
    the deadline for the Commonwealth’s filing had passed, and even longer after the court
    had stated that it would issue an opinion. See Commonwealth v. Herman, No. CP-67-
    CR-2400-2014, Order (C.P. York Feb. 3, 2015) (indicating that the court would issue an
    opinion within 30 days, or by March 5, 2015).
    Under these unusual circumstances, and particularly where the habeas petition in
    question implicates multiple issues, the normal waiver rules concerning the specificity of
    the contents of an appellant’s concise statement are relaxed. See Ryan v. Johnson,
    
    522 Pa. 555
    , 560, 
    564 A.2d 1237
    , 1239 (1989); Hess v. Fox Rothschild, LLP, 
    925 A.2d 798
    , 804 (Pa. Super. 2007). See generally Commonwealth v. Hess, 
    570 Pa. 610
    , 619
    n.9, 
    810 A.2d 1249
    , 1255 n.9 (2002) (citing Ryan for the position that the rule requiring
    an appellant to file a 1925(b) statement upon the court’s directive “may not be employed
    as a trap to defeat appellate review”). Here, the Commonwealth filed a timely statement
    and alleged, generally, that the county court had erred in granting Appellee’s habeas
    petition. This satisfied the dictates of Ryan.
    [J-124-2016] - 33
    Accordingly, we reverse the holding of the court of common pleas as respects
    the designer-drug charge.
    III. Conclusion
    For reasons given above, we affirm in part, reverse in part, and remand for
    further proceedings consistent with this opinion.
    Justices Baer, Dougherty and Mundy join the opinion.
    Justice Donohue files a concurring and dissenting opinion in which Justices Todd
    and Wecht join.
    Justice Wecht files a concurring and dissenting opinion in which Justices Todd
    and Donohue join.
    [J-124-2016] - 34