Rule 5.607 Who may impeach a witness

If you put a witness on the stand, you're not stuck with everything they say. This rule means that any side in a case, even the side that called the witness to testify, can challenge that witness's honesty or believability.

In practical terms, this matters if a witness surprises the party who called them by giving unhelpful or unexpected testimony. That party isn't forced to just accept it. They can point out reasons the witness might be wrong, mistaken, or not telling the truth, just like the opposing side could.

This is different from older rules that used to say you couldn't attack your own witness's credibility. Iowa's rule removes that restriction, so all parties are treated the same way when it comes to questioning a witness's reliability, no matter who brought that witness into the case.