Axel passed away last month, just a few years after retiring from the police force.He was living with his ex-girlfriend, who had adopted him.Friends of Central Fall Animals, a local nonprofit animal group, paid tribute to the dog, praising him as an excellent officer."Axel was all business on the streets," according to the post."He did a fantastic job of keeping the streets safe, and he always made sure our officers were safe, no matter how dangerous the situation was."The post also discusses Axel's friendship with Officer Decristoforo."He would not have hesitated to give his life to save the life of a fellow officer, particularly his partner," according to the post."These two were instantly best friends who were sure to have each other's back."With the officer's permission, they also shared a devastating photo of Decristoforo with Axel in his final moments: