Rule 207.1.Motion to Exclude Expert Testimony Which Relies Upon Novel Scientific Evidence.
Adopted January 22, 2001 · Not amended since adoption · Last verified June 30, 2026
Full Text of Rule 207.1
Plain-English Summary
This rule channels the pretrial challenge to novel scientific expert testimony — Pennsylvania’s version of a Frye motion. A party moves to exclude an expert’s testimony as inadmissible under Pa.R.E. 702 or 703 on the ground that it rests on novel science.
The motion must be specific. It identifies the expert and credentials, summarizes the expected testimony and pinpoints the portion challenged, states the basis for exclusion with specificity, sets out the evidence relied on, and attaches the relevant curriculum vitae and expert reports.
The court controls timing. It first reviews the motion to decide whether, in the interest of justice, the issue should be addressed before trial; it may instead defer admissibility to trial. The opposing party need not respond unless the court orders a response after deciding the matter belongs pretrial. A party is not required to raise expert-admissibility before trial unless ordered to.
Frequently Asked Questions
What is a Rule 207.1 motion?
It is a motion to exclude expert testimony that relies on novel scientific evidence, on the ground that the testimony is inadmissible under Pennsylvania Rule of Evidence 702 or 703.
Does the court have to decide the motion before trial?
No. The court first reviews the motion and may decide, in the interest of justice, to address it before trial or to defer the admissibility question until trial.
Does the other party have to respond to the motion?
Not unless the court orders a response. The court requires a response only if it determines the matter should be addressed before trial.
Official Note
Official Note: This rule establishes procedures for motions to exclude expert testimony which relies upon novel scientific evidence. The rule does not address the requirements for the admission of expert testimony under Pa.R.E. 702 and 703, which are governed by case law. It also does not address motions under those rules on other grounds. The court has discretion in the manner in which it determines the motion. While depositions of expert witnesses and evidentiary hearings are available to the court for this purpose, they should be utilized in limited circumstances. See the limitations set forth in Rule 4003.5 governing discovery of expert testimony. 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. When a ruling on a pre-trial motion to exclude the testimony of an expert witness is deferred until trial, the trial judge may choose to decide the motion (1) before the expert witness testifies on the basis of evidence offered outside the presence of the jury or (2) after the expert witness testifies on the basis of testimony offered at trial, in which event the trial judge will strike the testimony of the expert witness if it is found to be inadmissible under Pa.R.E. 702 or 703. However, hearings on preliminary matters must be conducted outside the presence of the jury ‘‘when the interests of justice require.’’ See Pa.R.E. 104.
Amendment History
The provisions of this Rule 207.1 adopted January 22, 2001, effective July 1, 2001, 31 Pa.B. 629.