§ 40.345 Rule 607. Who may impeach

Any side in a case can challenge a witness's honesty or reliability, even the side that called that witness to testify in the first place.

This matters because sometimes a witness doesn't say what a party expected, or new information comes up that makes the witness look less trustworthy. Before this type of rule existed, lawyers were often stuck with whatever their own witness said, even if it hurt their case. Now, if your own witness gives surprising or questionable testimony, you're allowed to point out problems with what they said or with their credibility.

This rule applies equally to everyone in the case. It doesn't matter if you're the person who brought the witness to testify or the opposing side. Both sides have the same right to question a witness's truthfulness or point out reasons the jury might not want to believe them.