Billie the sperm-sniffing police dog recruited to track down rapists

© Derbyshire police
Police in Derbyshire have employed a specially-trained dog, Billie the cocker spaniel, to track down sex offenders by sniffing out their semen.

Unlike many police dogs that specialize in identifying drugs, bombs or blood, Billie is trained to find DNA evidence used in sex cases by tracking down traces of human sperm.

His nose is so sharp he can detect as little as a milliliter of semen, which is about a third of the average ejaculation, more than a year after it was deposited indoors.

Billie can even smell eight-week-old sperm outside if it is “protected from the worst of the weather.”

Dogs are believed to have a sense of smell that is about 10,000 times more acute than that of humans. Those well trained can pick up some smells when they are diluted down to a few trillionths of a liter.

Billie and his handler have completed 18 searches since his first deployment in March, and the dog has detected the presence of semen at eight of these scenes.

In one case, Billie was called in to search a set of steps in one Derbyshire town where a rape had allegedly taken place.

He indicated the presence of semen and a swab was analyzed, proving a DNA hit. A man has since been arrested.

Superintendent Dick Hargraves said Billie is a “real asset.”

“He’s already been used in numerous investigations and has found evidence that has resulted in crime scene investigations identifying DNA profiles.

“We are always looking for ways to improve our service and we’re hoping that Billie’s skills will lead to more convictions.”