The former insurance salesman and trained nurse was identified as the killer after he voluntarily gave a DNA test earlier this year after he was caught stealing scrap metal. Police found his genetic data to perfectly match DNA clues found in the case of 17-year-old Angelika S who was raped and strangled on Sept. 1, 1984 while hitchhiking.

The news of the killer's arrest came as police in Aachen, southern Germany, were preparing to conduct mass genetic testing on 150 people who lived in the vicinity of the victim.

Police said the man had admitted to murdering five women and girls between 1983 and 1990. The victims, who ranged in age from 15 to 31, all came from the area around the city of Aachen near Germany's border with the Netherlands and Belgium.

Police said the crimes all followed the same pattern: the killer picked up young women and girls at night, often hitchhikers who wanted to get home from the disco. He then tied up the women and raped them before strangling them. The corpses were found days, or in some cases, months later in the surrounding woods.

Police relieved

The cracking of the cases comes as a relief to investigators in Aachen. Despite broadcasting the cases on the German TV show version of "America's Most Wanted," aimed to capture dangerous criminals, as well as enlisting the help of trained criminal profilers, police struggled for years to make any headway in the probes.

Investigator Uwe Breuer told news agency AP that in the last 17 years since the last crime was committed, police had repeatedly reopened the cases and searched for clues without luck.

Police said it was possible that the serial killer could be responsible for further crimes and hence were considering widening the investigations to neighboring Belgium as well as the Netherlands.