Impeachment of Defendant's Character Witness (F.R.E. 404, 405) is a procedure in which a party in a court case questions the credibility of a witness for the opposing party. Federal Rule of Evidence (F.R.E.) 404 and 405 govern the impeachment of a defendant's character witness. F.R.E. 404 states that evidence of a person's character or character trait is not admissible to prove that the person acted in accordance with the character trait on a particular occasion. However, evidence of a character trait may be admissible to attack or support the credibility of a witness. F.R.E. 405 sets out the different types of impeaching evidence that may be used to impeach a defendant's character witness. These include reputation or opinion evidence, evidence of specific instances of conduct, and a conviction of a crime. Reputation or opinion evidence is evidence of the witness's general reputation or opinion of the witness's character for truthfulness or untruthfulness. Evidence of specific instances of conduct refers to evidence of specific acts that a witness committed that would have an impact on the witness's credibility. Finally, a conviction of a crime is evidence of a crime that the witness has been convicted of. In summary, Impeachment of Defendant's Character Witness (F.R.E. 404, 405) is a procedure in which a party in a court case questions the credibility of a witness for the opposing party. The types of evidence that can be used to impeach the witness are reputation or opinion evidence, evidence of specific instances of conduct, and a conviction of a crime.