A specially-trained pooch is helping Derbyshire police probe sexual offences - by sniffing out sperm.
Billie and his handler have completed 18 searches since his first deployment in March and the dog has detected 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 forensically analysed, proving a DNA hit. A man has since been arrested.
Billie is able to detect stains on a range of surfaces and has detected stains more than a year old.
Superintendent Dick Hargreaves, of Derbyshire Constabulary, said: "Billie was first deployed in March this year after undergoing intensive training.
"He is a real asset and we share his expertise with other forces that need him.
"He's already been used in numerous investigations and has found evidence that has resulted in crime scene investigators identifying DNA profiles.
"We are always looking for innovative ways to improve our service and we’re hoping that Billie’s skills will lead to more convictions."