The difficult task of defending Dahmer was laid chiefly in the lap of expert Dr. Fred Berlin, founder and director of the Johns Hopkins Sexual Disorders Clinic from 1980 to 1992, and then founder and director of the National Institute for the Study, Prevention and Treatment of Sexual Trauma in Baltimore. In the first day of his testimony, Dr. Berlin makes the case that Dahmer was insane due to his necrophilic drive (his compulsion to have sexual encounters with corpses), a rare type of paraphilia. The main question Dr. Berlin needs to answer is whether Dahmer was able to prevent himself from killing or not. He argues that Dahmer tried many times to stop himself, only to give in when an opportunity arose. Finally, in November 1987, when Dahmer was living with his grandmother, he believed he had finally overcome his urges. One night that month, he met 25-year old Steven Tuomi at a bar and persuaded him to return to the Ambassador Hotel, where Dahmer had rented a room. The following morning, Dahmer said he awoke to find Tuomi lying beneath him on the bed, his chest “crushed in” and blood seeping from his mouth, with bruises on Dahmer’s own fists and one forearm; he stated he had absolutely no memory of having killed Tuomi, and later informed investigators that he simply “could not believe this had happened.” When he realized he was going to kill even despite himself, when he had no memory of it, he decided there was not point trying to stop, and he began instead to actively seek out victims.

There’s also an explanation of what the paraphilias are, with particular emphasis on necrophilia.

Listen to Dr. Berlin’s testimony here.

Watch the testimony on Youtube