Heidelberg (Germany), July 13 (DPA):  DNA tests not available in 1980 have caught a killer 29 years later, with a former male prostitute receiving life imprisonment Monday.

While police powers to prosecute murder never expire in Germany, the long delay was unusual.

Police stumbled on the 55-year-old suspect by chance after he was repeatedly caught riding city trams without a ticket. They took a routine DNA sample when they booked him at the police station.

While homeless and working as a gay prostitute, the man had been picked up by the victim, 60, in June 1980. He was convicted of bludgeoning and choking the victim to death in his home in Leimen, near Heidelberg, and leaving with the victim's cash.

At trial the accused declined to testify, but judges in Heidelberg said DNA tests and a fingerprint clearly linked him to human samples preserved from the scene of the previously unsolved crime.

His lawyers immediately filed an appeal against the conviction and life sentence.