The Mutilator (1984)

As a child, Ed was cleaning his father’s hunting rifles - a surprise birthday treat for the old man - when one of them went off, hitting and killing his mother. On seeing the bloodshed, his father flew into a murderous rage - Ed just barely escaped with his life. Now in his teens, he returns home; he doesn’t expect to find his father, still there, waiting for a chance to settle the score . . .