Articles

When questioning witnesses, the principle of impeachment simply means the introduction of evidence that may cast doubt on the credibility of the witness or the validity of the testimony. There are countless ways to impeach a witness. California Evidence Code section 780 identifies the most common methods, but they are expressly non-exhaustive: “[T]he … jury may consider in determining the credibility of a witness any matter that has any tendency in reason to prove or disprove the truthfulness of...

When it comes to impeachment—attacking the credibility of a witness—lawyers sometimes fail to consider whether the evidence is substantive or pure impeachment. It can lead to an exchange like the following:

Judge: Are you offering this evidence as pure impeachment or to establish its truth?

Lawyer: Yes.

Knowing whether impeachment evidence may also be substantive is important. Substantive evidence “is offered to establish the truth of a matter to be determined by the trier of fact.” Chiasson ...