Jail Time

Oliver finds himself in a police station, being questioned about the murders of three people. Presented with DNA, photo, and video evidence of him killing them, he's shocked, and rightfully so. He knows he didn't do it, so who did? Nonetheless, he's put in jail for the crimes. Detective Michael Pierce hesitantly believes Oliver and decides to look into the case himself. Can he figure out who did it before Oliver gets put in jail, or is Oliver actually the killer?