On April 29, 1989, 17-year-old Jeffrey Pelley put on his tuxedo and headed to his high school prom in Lakeville, Indiana. But the next morning, when his father, Pastor Robert Pelley, didn't show up for Sunday service, a horrifying discovery was made next door at the parsonage. Robert, his wife Dawn, and their two young daughters had been gunned down with a shotgun. The front door was locked, the curtains were drawn, and the primary suspect was the son who had supposedly spent the night dancing.