Dead Air

S1, E10: Claiming that a caller strangled someone to death during her show, radio psychiatrist Christina Noble turns to the police for help. Although Stonetree and Schanke suspect a hoax to improve her show's ratings, Nick is convinced that Christina is telling the truth, but is unable to find the killer before he claims another victim on the air. After finding the first victim's body, Schanke and Nick monitor the station's phone lines, hoping to trace the killer's call when he phones again. When he hangs up before the trace can be completed and leaves them with nothing to go on, Christina blames herself for losing the killer. So, after Schanke finds another of his victims, Christina offers to help find the killer before he can strike again. As she is helping with a psychological profile of the suspect, Christina tells Nick about Matthew Reid, a former patient who killed his mother after being released from a hospital, prompting her to abandon her medical practice. Surprised by a call from Matthew, Christina agrees to see him at his hotel, but when Schanke comes across his records during the investigation, Nick realizes that Reid is the suspect they are after. With no other way to find her, Nick poses as the host of a radio show, prompting Matthew to call in. Keeping him on the phone, Nick is able to trace the call but, realizing his mistake, Matthew forces Christina to the hotel's roof. Stopped before he can kill her, Matthew then turns his gun on Nick but accidentally backs into an electrical transformer, killing himself and ending his murder spree.