I'm no legal expert, but I think some duplicated evidence can be introduced in court as long as both sides stipulate it's the best anyone could produce. I had a friend who was an expert on videotapes, and he had to testify that the surveillance tape he examined was not the original copy. The FBI gave him a first generation copy, which was still good enough for him to form an opinion. The court allowed it because both sides agreed it wasn't doctored or edited. It looked just like the original tape found in the store's camera.