Episode 6: Stepbrother
By his own admission, Mark Dempsey has spent a lot of time in jail over the course of his life.
You learn a lot of things from that experience, according to Mark.
There's an unwritten code: don't put anything on yourself, don't speak to the police, and... don't be a rat.
The same often applies across the bonds between friends and family.
Michael Lavoie was a partner in crime, according to Mark, who says the two undertook robberies together.
But Lavoie was also family.
Mark and Michael became stepbrothers when they were young boys.
They grew up together, shared friends, worked at the same job.
But the two had a falling out when Mark discovered that Mike had been having an affair with Sheila Darbyson.
This was also around the same time that Sheryl Sheppard went missing.
Mike and Sheila's affair can still grate on Mark Dempsey when he talks about it.
But some of the other things he's noticed and experienced over the years with Michael Lavoie don't add up.
Does Mark know something that could help the Sheppard case?