Did Dr. Sam Sheppard kill his wife? With the help of advanced technology, NOVA re-examines the 1954 murder of Marilyn Sheppard and the subsequent trials of her husband, Dr. Sam Sheppard. With a detailed reconstruction of the Sheppard house, access little-known evidence, and hear insights from noted experts, America's most intriguing unsolved murder reveals fascinating new clues... and surprising new suspects. Then, follow the FBI's psychological detectives as they race against time to penetrate the mind of a serial killer- and stop him from striking again. And finally, trail along with fire sleuths as they discover the mysterious source of a series of L.A. store fires, and capture a surprising suspect filmed by NOVA.