What if I don't believe the witness in the trial?
Be skeptical of anyone who's a witness, for either side, and remember that often all the evidence is not going to be presented in court, and you're not going to know it because the judge may have ruled that it's not relevant, and some of the evidence that is presented may not be true. You have to be your own personal sleuth in this case, that's why you have to pay attention to body language and facial gestures and what's going on and the credentials of forensic witnesses. Pay attention, and be skeptical.