A police force in the East Midlands region of England is using a sniffer dog, specially trained to track down traces of human semen, to help them in their hunt for rapists.
Derbyshire Constabulary are using the services of Billie the cocker spaniel, whose nose is trained to find DNA evidence used in sexual assault cases.
“He’s already been used in numerous investigations and has found further evidence that has resulted in crime scene investigators identifying DNA profiles,” Superintendent Dick Hargreaves of Derbyshire Constabulary told ‘The Times’.
“We are always looking for innovative ways to improve our service and we’re hoping that Billie’s skills will lead to more convictions,” he said.
The cocker spaniel’s nose is so sharp that he can detect as little as a millilitre of sperm, about a third of the average ejaculation, more than a year after it was deposited indoors.
He can even catch the faint whiff of eight-week-old semen outside if it is “protected from the worst of the weather”, a leaked police briefing reveals.
Since March this year, Billie has already carried out 13 live searches, according to a document drawn up by Derbyshire police.
Dogs are believed to have a sense of smell that is about 10,000 times more acute than that of humans.
Dogs trained by South Yorkshire police to find bloodstains have previously picked out deposits 14 years after the crime.
The typical dog has several hundred million olfactory receptors in its nose, compared to about six million in humans.
If you scaled up a dog’s brain to the same size as a person’s, the region that processes scents would be 40 times the size of humans.
Dog noses also channel air into separate airways for sniffing and breathing. PTI AK PMS