A witness’s credibility is a critical issue for both the defense and the prosecution at a criminal trial. Witness’s credibility can make or break a case for a criminal defense attorney and so it is important that your attorney properly investigate any witness’s background regardless of whether or not they are being called as a defense or prosecution witness. In Pennsylvania the credibility of the witness can only be attacked in the form of reputation as to that witness’s character. This Rule of Evidence (Rule 608) differs from the Federal Rule of Evidence (608) which allows opinion evidence. While the Federal Rules allow opinion evidence neither Pennsylvania nor the Federal Rules of Evidence allow the opposition to attack a witness’s credibility through extrinsic evidence of a specific instance of conduct. The exception to this Rule, however, is prior criminal convictions.
The Federal Rules of Evidence (Rule 608) do, however, allows the opposing party to cross examine the witness on a specific instance of conduct in two situations: (1) where the specific instance of conduct is probative (proving or demonstrating) of a witness’s own character of truthfulness and (2) when they concern the character for the truthfulness of another witness whom this witness has testified about. Pennsylvania does sometimes allow a cross examining attorney to question a witness about specific instances of conduct but only those acts which affect the credibility of the witness. Courts will only allow such questioning if the attorney asking the questions has a reasonable basis for the question.
It is important to understand that different rules of evidence govern the impeachment of a witness (attacking credibility) and the character of a witness. Unlike impeachment, character evidence is normally not admissible unless it is introduced into evidence. The character of the accused is never admissible unless the accused introduces it or the prosecution offers it by filing a pre-trial motion (this is commonly called a prior bad acts motion). The character of a victim is also never admissible unless the accused introduces it into evidence (assault cases – victim’s tendency towards violence). It is important to understand, however, if the accused introduces character of the victim, it “opens the door” to the character of the accused. The character of all other witnesses excluding the victim and the accused is admissible according to the Rules that govern witness impeachment.
The bottom line is that character evidence is usually not admissible in court unless it is offered or it falls under the impeachment rules of evidence. If you have more questions about character evidence or criminal procedure I encourage you to read my book and watch my videos.