David's stepbrother could politely be described as "extremely impressionable" and "not very bright". Unfortunately for David, his stepbrother's programmability meant that he had been easily recruited into a sadist's neo-Nazi gang. When the gang leader decided that he wanted to play with David, at first his stepbrother was reluctant - but the leader kept hassling him, so he gave in and lured David to the gang's new facility.
After torturing David for a while, the gang leader sent his henchmen off to drain his bank account. The pin didn't work, and the henchmen retured - to find David dead. According to the gang leader, he'd "wimped out" (He'd tried to fight back) and the gang leader had strangled him. Distraught that he had missed out on the hours of "fun" he'd been looking forward to, one of the gang's co-leaders settled for frying up a piece of his thigh to share with the boss before putting the rest of the corpse in the acid barrels with the others.
David was the final victim of the gang - the earlier murder of a gang member's wife had finally put investigators onto the Nazis' trail, and they would shortly be captured.