Keaton's Cop (1990)

Ex-mobster Keaton, now living in a retirement home, narrowly misses being the target of a mob hit. Policemen Jake, an old friend of Keaton, and Gable, a violent cop who takes an immediate disliking to the aging gangster are called in to keep Keaton safe, as well as investigate the hit. There is a turn of events though when Jake is killed by the hitmen, Gable and Keaton are forced to get along while they search for whomever killed their friend and partner. Adding to the challenge, they only have forty-eight hours to solve this case on their own.