A sadomasochistic serial murderer accidentally killed himself in his prison cell after performing a sex act that involved electricity and his genitals.
Police in Germany said Egidius Schiffer, 62, accidentally died while performing the 'autoerotic act' and that there was no reason to suspect foul play or suicide.
Schiffer was known as the 'Aachen Strangler' after he was jailed for murdering five female hitchhikers between 1983 and 1990.
Candida Tunkel, a spokeswoman for Bochum prison in northwest Germany, said a cable from his bedside lamp was used during the sex act, The Times reported.
A post-mortem revealed the cause of death was heart failure caused by a surge of electricity through his chest.