Stella, who was dumped on the streets last year, is now helping the force to sniff out drugs.
The dog, thought to be 18 months old, recently managed to complete her six-week police training course in just four weeks.
She can now search for a range of illegal drugs as well as money, guns and ammunition.
On her first day on the job Stella sniffed out a £200 wad of cash in an underwear drawer.
PC Claire Todd, of Gloucestershire Police, who became her handler in January, said: “I had never owned a Staffordshire bull terrier before but when I recruited Stella her drive was phenomenal. I was so impressed with her.”
Staffies have long been associated with hoodies and hooligans and have been blamed for many attacks on people.
Claire added: “It’s really positive that even though bull terriers have a reputation for being fighting dogs, they’re actually not all the same.