German police said Friday they believe they have caught a serial killer after a 64-year-old man arrested over a 1984 murder confessed to killing four more women between 1969 and 1972. The man, arrested in April for the murder of 18-year-old Gabriele Stender with the help of DNA evidence, admitted to the unsolved murders in northern Germany, police and prosecutors in Kiel said. He confessed after his arrest to raping and strangling Stender, whose body was found in woods nine days after her disappearance. He was one of 150 people who gave saliva samples to investigating police at the time.