MBE Fast Fact: Impeachment with Specific Instances of Conduct

Except in regards to impeachment by conviction of a crime, a witness cannot be impeached with specific instances of conduct by extrinsic evidence. Rather, to impeach a witness by specific instances of conduct, the witness must be asked about those instances on cross-examination. In addition, it must be true that the specific instances of conduct are probative of truthfulness or untruthfulness.

In other words, it’s proper to ask a witness on cross-examinatin whether that witness was fired from his previous job for embezzling money from his employer (whether he embezzled money is probative of his truthfulness,) but it would be improper to ask a witness on cross-examination whether the witness was fired from his last job for verbally abusing another employee (verbally abusing an employee is not probative of truthfulness).