A woman who donated her rescue spaniel to the police says she had a "happy cry" at the ceremony to mark the completion of his training.
Katie Ballance contacted Avon and Somerset Police after seeing the force's appeal for working dogs on social media.
She had been fostering Chester and was searching for a permanent home for him but feared he would be "passed around from home to home" because of his high energy.
Ms Ballance said she was happy knowing he would have "the best life a dog could have" with his handler.
Speaking to BBC West at Chester's graduation ceremony in Clevedon, Somerset, Ms Ballance said said got a call from police within hours of emailing them about Chester.
An officer came to conduct an assessment the following day, eight weeks later and he is now an official police dog.
"I could have found him any home in a heartbeat, but the way that he was, I knew that I would be contacted and they would say, 'we're having problems with Chester, we can't control him'," she said.
