Impeachment of a witness by prior conviction (F.R.E. 609) is a legal procedure that allows a lawyer to challenge the credibility of a witness by introducing evidence of a previous criminal conviction of that witness. This procedure is allowed under Federal Rule of Evidence 609, which states that evidence of a witness's prior conviction for a crime that is punishable by death or imprisonment in excess of one year may be admissible for the purpose of attacking the credibility of the witness. There are two types of impeachment of witness by prior conviction: direct impeachment and indirect impeachment. Direct impeachment involves introducing evidence of the witness's prior conviction to the jury, while indirect impeachment involves questioning the witness about the prior conviction without introducing evidence of the conviction. In either case, the court must determine whether the probative value of the prior conviction outweighs its prejudicial effect.