One of the Finest (1919)

Traffic cop Larry Hayes takes care of four-year-old Mary Jane, the daughter of Gus Andrews, a criminal sent to prison because of Larry, and Nellie, a shop girl who visits often. After Larry reprimands Frances Hudson's chauffeur for speeding, and later reproaches Frances after he stops her runaway horse, she gets her influential father to transfer him. As a plainclothesman guarding the gifts at a wedding in the Hudson home, Larry courts Frances, but their mutual attraction disturbs Frances' suitor Teddy. After Mr. Hudson learns that Larry's deceased father, a police commissioner, was his old friend, he has Larry assigned to guard his house. Teddy finds out that Mary Jane calls Larry "Daddy," and tells Frances. Frances is suspicious when she sees Nellie warn Larry that Gus is out of prison, and has vowed revenge. After a gun duel in which Gus is wounded, however, the truth is told. Larry then gives up his job to become a "poor lawyer," and marries Frances.