If your parents used to warn you about accepting candy from a stranger, this man is the reason why. Back in 1974, on Halloween, O’Bryan gave his very own 8-year old son, his daughter, and two other kids Pixy Stix candy laced with cyanide. His son was the only one who ate it and died. But what makes it worse is that O’Bryan decided to kill his kid to cash out on a life insurance policy because he was in debt for $100,000.