Flood Tide (1957) on Netflix

Plot summary

Bill Holleran insists the boy is lying, but he is convicted of murder on the testimony of ten-year-old David Gordon, who says he saw him shove a man into the water. Bill has rented a beach cottage from Steve Martin, an engineer who comes home from an assignment overseas and goes to the district attorney's office to speak for him. Bill mentions that he once dated David's mother, Anne. Steve remembers the previous summer, when he met David on the beach, saw the braces on the boy's legs, and apologized to Anne, who explained that a car accident five years earlier had injured David's spine and killed her husband. Steve gives David a radio, and the boy, sensing the pull between Steve and his mother, acts ungrateful.