Cop for a Day: Alfred Hitchcock Presents (TV Episode)

Plot

Hoodlums Phil (Walter Matthau) and Davey (Glenn Cannon) stage a daring daylight robbery of a bank messenger, whom hotheaded Davey shoots and kills. It turns out that there was a witness to the murder, a young woman (Carol Grace) now in police custody. Scheming to knock off the witness before she can identify Davey, Phil disguises himself as a policeman and worms his way into the woman's confidence. ~ Hal Erickson, Rovi