"On TV and in real life, forensic science plays an important role in criminal convictions," John Oliver said on Sunday's Last Week Tonight, but not all forensic science is as reliable as we've been led to believe by TV shows. Jurors don't always know that, but they expect forensic proof — what prosecutors call the "CSI effect." Since Oliver had a lot of potential jurors watching, he took a few minutes to educate, entertainingly. "It's not that all forensic science is bad, because it's not," Oliver said.