Hawaii Five-O (1968)

S4E6 ...And I Want Some Candy And A Gun That Shoots

Billy Shem Jr., a young marksman and Vietnam veteran, acquires a rifle through deceptive means and heads to a bunker at Diamond Head. From his hidden perch, he begins firing at passing motorists and eventually targets the responding police officers. As the situation escalates, McGarrett is determined to stop Billy's dangerous rampage using any necessary tactics.