Revising Comment to Rule 578 of the Pa. R. Crim. Pro.

FINAL REPORT1

Revisions to the Comment to Pa.R.Crim.P. 578

PRETRIAL RESOLUTION OF ADMISSIBILITY OF EXPERT TESTIMONY

On September 21, 2017, effective January 1, 2018, upon the recommendation of
the Criminal Procedural Rules Committee, the Court approved the revision of the
Comment to Rule 578 (Omnibus Pretrial Motion for Relief) to encourage the pre-trial
resolution of the admissibility of scientific or expert evidence. In particular, the revision
adds to the list of types of relief that may be sought in an omnibus pretrial motion
proposing or opposing the admissibility of scientific or expert evidence.
The Committee recently examined the question of the pretrial determination of
the admissibility of expert testimony. This was prompted by Justice Dougherty’s
dissenting opinion in Commonwealth v. Safka, 141 A.3d 1239 (Pa. 2016). At issue in
Safka was the trial court’s sua sponte allowance of the Commonwealth to establish the
reliability of the scientific evidence after the Commonwealth had rested. In his dissent
from the majority’s upholding of the trial court’s action, Justice Dougherty noted that this
issue could have been avoided had the particular scientific evidence’s reliability been
challenged earlier than at trial as it had been. Acknowledging that the defense did
nothing improper under the current rules, he recommended that the Committee examine
rule changes that would encourage the pretrial resolution of these types of challenges.
In undertaking this examination, the Committee first reviewed the law regarding
admissibility of scientific evidence and the procedural mechanisms to address the
question. Frye v. United States, 293 F. 1013 (App. D.C. 1923) is the seminal case
1
The Committee's Final Reports should not be confused with the official Committee
Comments to the rules. Also note that the Supreme Court does not adopt the
Committee's Comments or the contents of the Committee's explanatory Final Reports.

Pretrial Resolution of Admissibility of Expert Testimony Final Report: 09/21/2017
establishing the test for the admissibility of scientific evidence. The Frye test requires
the proponent of scientific evidence to establish that the theory and method used by the
expert witness were generally accepted within the relevant scientific community.
Although modified in a number of jurisdictions by acceptance of the holding in Daubert
v. Merrell Dow Pharmaceuticals, Inc., 509 U.S. 579 (1993) and Kumho Tire Co. v.
Carmichael, 526 U.S. 137 (1999), Pennsylvania still adheres generally to the Frye test
and this standard is recognized in Rule of Evidence 702. Rule of Evidence 703 also
enumerates the basis for expert opinion testimony.
Neither of these rules of evidence addresses procedures for raising such
challenges. Pennsylvania Rule of Civil Procedure 207.1 provides specific procedures
for raising challenges to scientific evidence. However, as Justice Dougherty notes in
the Safka dissent, the civil rule does not provide for specific timing but is primarily a
content rule. In fact, paragraph (b) of Pa.R.C.P. 207.1 states that a party is not required
to raise the admissibility of expert testimony pre-trial unless the court so orders. There
is language in the Official Note to Pa.R.C.P. 207.1 providing some guidance as to the
pretrial determination of such issues:

In deciding whether to address prior to trial the admissibility of the testimony of
an expert witness, the following factors are among those which the court should
consider: the dispositive nature or significance of the issue to the case, the
complexity of the issue involved in the testimony of the expert witness, the
degree of novelty of the proposed evidence, the complexity of the case, the
anticipated length of trial, the potential for delay of trial, and the feasibility of the
court evaluating the expert witness’ testimony when offered at trial.

However, this guidance is directed toward the judge in deciding the issue and not
toward the parties regarding the time for raising such issues.
The Rules of Criminal Procedure do not provide specific procedures for raising
Frye issues. Frye challenges generally are raised as motions in limine but the rules do
not provide for any specific timing for raising these motions. Rules 578 and 579 require
an omnibus pretrial motion to be served within 30 days of arraignment and a court to
determine all pretrial motions before trial. However, motions in limine are distinguished
from the omnibus pre-trial motion (and its timing provisions) in the Rule 578 Comment.

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 The Committee noted that the federal system encourages the pretrial
determination of challenges to expert testimony. For example, the Third Circuit has
emphasized the importance of conducting in limine hearings under Fed. R. Evid. 104
(resolution of preliminary questions) when making reliability determinations required by
Fed. R. Evid. 702 and Daubert. Padillas v. Stork-Gamco, Inc., 186 F.3d 412, 417 (3d
Cir. 1999). However, this is based heavily on the gatekeeping function that is placed on
the trial court by Daubert and such motions may still be brought during trial. See, e.g.,
Smoot v. Mazda Motors of America, Inc., 469 F.3d 675, 676 (7th Cir. 2006).
Based on a review of the foregoing, the Committee concluded that the rules
should encourage the pre-trial determination of the admissibility of expert testimony.
However, the Committee did not believe that it would be effective to create a specific
deadline by which time the motion must be filed, given the wide variations of the types
of evidence involved and the circumstances under which the evidence is discovered.
The Committee decided that the question would be best addressed by adding a general
provision to encourage pre-trial determination of these issues. Therefore, the Comment
to Rule 578, which contains a list of suggested types of pretrial motions to be included
in the omnibus pretrial motion, has been revised by adding to that list those motions that
would “establish a challenge to the admissibility of scientific or expert evidence.”2
One of the issues that the Committee discussed was the question of whether or
not adding these types of motions to the Rule 578 Comment list of suggested motions
would now tie them to the time limitations for omnibus pretrial motions. The Committee
first noted that the time limitations for filing omnibus motions often are treated more
flexibly by most courts, given the wide variations of issues raised. More specifically, the
Committee believes that if there is a legitimate question concerning the reliability of
scientific evidence, a trial judge would permit it to be raised even if it was after the Rule
578 time limit. The Committee discussed removing the Rule 578 Comment language
referring to motions in limine but decided that there are motions in limine unrelated to

2
Additionally, a typographical error in the numbering of the list would be corrected.

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Frye issues that should continue to be exempt and did not want to confuse the issue.
The Committee ultimately agreed to add language to the Comment that would
state that the pre-trial determination of Frye issues should be encouraged but that
raising these issues in a later motion in limine is permissible as well. Additionally, a
cross-reference in the Rule 578 Comment to Rules of Evidence 702 and 703, which
address more substantive aspects of the admissibility of expert testimony, has been
added. Finally, the revision adds a cross-reference to Frye and the chief Pennsylvania
cases applying it.

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