Under Pennsylvania Rules of Evidence, during trial, either party may attack the credibility of any witness with evidence that the witness has been convicted of a crime involving dishonesty or false statement. Generally, the conviction or the date of release from confinement, whichever is later, must be within 10 years from the date at which the witness is being impeached.
If the witness is the defendant in a criminal case, this rule does not allow the Commonwealth to directly confront the defendant with his conviction for dishonesty. Instead, after the defendant has completed his testimony, the Commonwealth must call a rebuttal witness who testifies to the fact that the defendant was found guilty and the crime of which he was guilty.
If the witness is not the defendant, the party who seeks to attack the credibility of the witness may do so directly by asking the witness questions and using any court documents that reference this conviction.
At the conclusion of the trial, the trial judge will read an instruction to the jury that states that a jury may disregard any witness' testimony who has been convicted of a crime of crimen falsi, if the jury so chooses.