Rule 607 Who May Impeach a Witness

Any person who testifies in court can have their honesty or reliability questioned. This is called impeaching a witness.

Either side in a case can challenge a witness's credibility, even if that side was the one who called the witness to testify. So if you put someone on the stand and their testimony hurts your case, you are not stuck with it. You can try to show the jury reasons not to fully believe that witness.