Jeffrey Dahmer's 2 Psychiatric Evaluators' Findings

Jeffrey Dahmer was a serial killer & sex offender who was sentenced to 16 life sentences for the murder and dismemberment of 16 boys between 1978 and 1991. The heinous charges included necrophilia and cannibalism. Dahmer pled guilty due to insanity.

To support the insanity plea, the defense attempted to use the necrophilic acts as evidence of Dahmer's crimes resulting from uncontrollable passion. Regardless of the verdict, it was clear Dahmer would spend the rest of his life detained either in prison or a mental hospital.

Psychologist Dr. Frederick Fosdal was hired by the prosecution and evaluated Dahmer in 1992 and testified in court about Dahmer's clinical diagnoses and about his mental state at the time he committed the crimes.

Dr. Fosdal spent 20 hours over 5 sessions interviewing Dahmer. He concluded and testified that Dahmer was not considered legally insane. He explained that it appears Dahmer had a sexual disorder, but that it did not inhibit his ability to follow the law.

Dr. Fosdal further explained that Dahmer's sexual acts with the men were disconnected from the killing and disposing of the corpses later. It seems the sex was enjoyed, whereas the murders were "administrative". He even specifically selected men without cars to limit evidence.

Dr Park Elliott Dietz was also hired by the prosecution to evaluate and testify about Dahmer's mental state. Dietz concluded that Dahmer was not at all impulsive, but that each murder was planned, deliberate and calculated.

Dr. Dietz also testified that Dahmer appeared to know right from wrong and could have stopped any killing, if needed, in order to hide. Dietz noted that Dahmer always put on a condom prior to his necrophilic acts. This was further evidence of his control and premeditation.

The evaluators seemed convinced that Dahmer's primary goal was a controllable, zombie-like sexual partner who he could manipulate and keep. A relationship with a real, living person would have been preferable, but this was something Dahmer was never able to attain.

Dr. Dietz labeled Dahmer's sexual behaviors as simply "unorthodox", but testified that he had the capability to function well in society ( at work and around others in public) and that he did not meet any of the recognized criteria of a personality disorder.

In the end, the court did not accept the insanity plea. The prosecution's portrayal of Dahmer being in control at all times and function hidden in society for years convinced the jury that insanity was not an appropriate diagnosis. For more Memos like this follow @sciencesimplified