Rapist Nabbed by Sperm-Sniffing Dog Rapports Opus is the only dog of his abilities in southern Sweden By Evann Gastaldo, Newser Staff Posted Jul 18, 2011 11:03 AM CDT 11 comments Comments A police dog, but not Rapports Opus. (Getty Images) (Newser) – Forget drug-sniffing dogs: Sweden has its very own sperm-sniffing dog named Rapports Opus, and he recently helped police catch an alleged rapist. Rapports Opus trained for a year to become the only sperm-sniffing dog in southern Sweden, and he was brought to a park where a man had been accused of forcing a woman to perform oral sex on him. There, the dog found traces of semen, which were matched with the 23-year-old suspect's DNA, the Local reports. The man was charged with rape, and Rapports Opus's trainer will testify at his trial. It will be the first time evidence discovered by the dog will be used in court.