The Keystone Kops with Charlie Chaplin in A Thief Catcher (1914) """

From Wikipedia:
A Thief Catcher is a one-reel 1914 American comedy film, produced by Mack Sennett for his Keystone film company, directed by Ford Sterling, and starring Sterling, Mack Swain, Edgar Kennedy, and Charles Chaplin as a policeman. Chaplin had claimed in interviews that he had played a bit role as a policeman while at Keystone Studios.