Alfred Hitchcock Presents: Backward, Turn Backward (1960)

Synopsis
Sixty-year-old gardener Phil Canby (Tom Tully) woos neither wisely nor well when he falls in love with 18-year-old Sue Thompson (Phyllis Love). Later on, Sue's father is killed, and Sheriff Willetts (Alan Baxter) arrests Phil for the murder. Protesting his innocence, Phil insists that he was babysitting his grandson on the night of the killing. The outcome of the story hinges on the sound of a baby's cry...but not from a baby. ~ Hal Erickson, All Movie Guide