Sam Anderson

Their Bible study group flocks to his side to lend prayer and guidance. But in the group's first meetup, just a couple days after Mark's release from custody, he seems more interested in debating them than receiving guidance.

Their Bible study group flocks to his side to lend prayer and guidance. But in the group's first meetup, just a couple days after Mark's release from custody, he seems more interested in debating them than receiving guidance.

From Sony Music Entertainment and Novel, I'm Sam Anderson. You're listening to The Arsonist Next Door. Episode 5, The Confession Back on the night of Mark's arrest, while he's sitting cuffed in the back of a squad car, Sergeant Trent Crump steps onto the front porch of Mark's home. It's one in the morning. Mark's wife, Peggy, and their 11-year-old daughter are asleep inside.

From Sony Music Entertainment and Novel, I'm Sam Anderson. You're listening to The Arsonist Next Door. Episode 5, The Confession Back on the night of Mark's arrest, while he's sitting cuffed in the back of a squad car, Sergeant Trent Crump steps onto the front porch of Mark's home. It's one in the morning. Mark's wife, Peggy, and their 11-year-old daughter are asleep inside.

Turns out, Peggy doesn't even know Mark isn't home. It will take investigators a few hours to get a search warrant. By the time the sun is rising over the preserve, Mark is still in custody. Lieutenant Rob Handy and FBI case lead Terry Kearns lead a group of officers to Mark's house to conduct a search.

Turns out, Peggy doesn't even know Mark isn't home. It will take investigators a few hours to get a search warrant. By the time the sun is rising over the preserve, Mark is still in custody. Lieutenant Rob Handy and FBI case lead Terry Kearns lead a group of officers to Mark's house to conduct a search.

After Special Agent Ken Williams finishes interviewing Mark at the police station, he heads over to the house too.

After Special Agent Ken Williams finishes interviewing Mark at the police station, he heads over to the house too.

The evidence they found doesn't directly link Mark to the fires. But there is something they find in Mark Sand's house that strikes the task force as potentially important. Something impossible to ignore.

The evidence they found doesn't directly link Mark to the fires. But there is something they find in Mark Sand's house that strikes the task force as potentially important. Something impossible to ignore.

Pornography. A lot of it.

Pornography. A lot of it.

Of course, there's nothing criminal about viewing pornography. But Rob suspects there might be something more serious tied up in Mark's porn obsession.

Of course, there's nothing criminal about viewing pornography. But Rob suspects there might be something more serious tied up in Mark's porn obsession.

A connection between the arson spree and the pornography.

A connection between the arson spree and the pornography.

It's not unheard of that arson attacks might have a sexual component. And judging by the fact that Mark was in his underpants on the night of the arrest, it's not much of a stretch for investigators to suspect that this might be part of the story too. On top of that, Mark has an extensive VHS collection, including a bunch of home movies.

It's not unheard of that arson attacks might have a sexual component. And judging by the fact that Mark was in his underpants on the night of the arrest, it's not much of a stretch for investigators to suspect that this might be part of the story too. On top of that, Mark has an extensive VHS collection, including a bunch of home movies.

The investigators think maybe they contain something related to the fires. Could he have filmed his targets beforehand? Or taken trophy footage of the burned homes? They confiscate every single tape and bring them back to the station. Trent Crump assigns a couple of investigators a new task.

The investigators think maybe they contain something related to the fires. Could he have filmed his targets beforehand? Or taken trophy footage of the burned homes? They confiscate every single tape and bring them back to the station. Trent Crump assigns a couple of investigators a new task.