the bolded is clipped from this article already kindly posted in this thread. Derek Percy | Murderpedia, the encyclopedia of murderers One of the problems with investigating Percy was that police did not have a sample of his DNA. Police in Victoria can by law take DNA samples from anybody convicted of a crime, but Percy was never convicted, having been found not guilty by reason of insanity. This legal loophole meant that police could not take his DNA. In at least one of the murders for which Percy is a suspect, it is believed that DNA from the crime scene has been preserved. these kind of prisoner rights have to stop. they should have had his dna since 1970 they have dna for wanda beach so thinking yes its derek percy cant wait for sunday night!