Laura Thompson Murder: Wife Rats Out Joseph Marshall Jr., Sean McDonough in Cold Case Rape, Slaying


The year was 1993, and Laura Lynn Thompson was a 15-year-old mother with a nine-month-old baby. In January of that year, she left her home in New Castle, Pennsylvania, purportedly to play cards with some unknown men. Then she disappeared…

Joseph Marshall Jr. made the mistake of confessing the murder to his wife, who secretly recorded the admission

At the time, it was thought that she might have run away. She would spend the next 17 years officially listed as missing. But that changed in June, when Shannon Marshall went to police with a wicked tale.

She was in the midst of divorcing her husband, Joseph Marshall Jr., and she was scared that he might kill her over what she knew. Back in 1993, while they were engaged, he’d admitted to her that he once killed someone. He didn’t say who at the time.

But later that year, she accompanied him to the woods of Pennsylvania. Shannon waited in the car as Joseph went into the woods and dug up Laura’s body. They then drove to a field where he scattered her remains.

Joseph later confessed to his wife that he’d taken part in Laura’s murder. He told her that he and Sean
McDonough invited Laura to hang out with them. They’d taken her to McDonough’s cabin in the woods. That’s where McDonough stabbed Laura to death, stripped her naked, and raped her.

Police tricked Sean McDonough into discussing the murder with Marshall over the phone

No doubt Joseph’s tale is a little suspicious, since he’s painting himself as an innocent bystander in all of this. And why a woman would willingly marry a guy who’s digging up bodies is anyone’s guess. But over the next 17 years, as their marriage began to crumble, Shannon secretly made a tape of Joseph confessing to the slaying.

In June, she became fearful of what her husband might do to her now that their marriage was on the rocks. So she went to police. They had her call McDonough, who had since moved to Louisiana, to say she had a recorded confession from her husband, and that she was worried he’d kill her.

That prompted a flurry of calls between McDonough and Joseph, which were recorded by police. It seemed that detectives had finally solved a case that had been left to mystery for nearly two decades. Both men have now been arrested and are facing murder charges in the case.

See our last story from the Cold Case file: Angus Pascall, NYC Paramedic, Busted as Serial Rapist Who Attacked Little Girls.