How did David Hayworth get undead on all your children?

He wasn't really dead...He took a drug to make it appear he was dead.It slowed his heart and breathing to where it would seem he was dead. He blackmailed the coroner to go along w/him.........

He just wanted it to appear that Ryan had killed him ,just to keep him away from Greenlee.But it backfired and Greenlee was the one found guilty and sentenced to LIFE in prison....He had to reappear and tell all in order to save her.