Let 'Er Go Gallegher (1928)

Young John Gallagher wants to be a newspaper reporter. One day he witnesses a murder committed by a mysterious man with only four fingers on one hand. He gives his account of the murder and a description of the killer to his hero, newsman Henry Callahan, resulting in his getting a job on the paper as an office boy. When circumstances arise that result in Callahan losing his job on the paper, he and Gallagher set out to discover the identity of the killer and help Callahan get his job back.