Narrator / Peter Van Sant

But Mark didn't start out rich at all. In fact, just the opposite. And his upbringing was far from easy.

But Mark didn't start out rich at all. In fact, just the opposite. And his upbringing was far from easy.

This is Victoria again, Mark's sister. They grew up in the Seattle area in the 1950s and 1960s.

This is Victoria again, Mark's sister. They grew up in the Seattle area in the 1950s and 1960s.

Their mother's second marriage also then fell apart.

Their mother's second marriage also then fell apart.

Mark struggled in school. According to Victoria, the family didn't know how to help him.

Mark struggled in school. According to Victoria, the family didn't know how to help him.

And then their mother's third husband died of cancer.

And then their mother's third husband died of cancer.

Mark got in touch with the family's old vet. He encouraged Mark to join the Washington State Search and Rescue Canine Unit.

Mark got in touch with the family's old vet. He encouraged Mark to join the Washington State Search and Rescue Canine Unit.

Mark eventually started to train dogs in private sessions where he'd go to people's homes. In a news article from 1981, Mark is described as a disciple of the famous behavioral psychologist B.F. Skinner. Skinner studied how rewards and punishment can condition behavior in humans. Mark applied that to dogs by training them with punishment and reward.

Mark eventually started to train dogs in private sessions where he'd go to people's homes. In a news article from 1981, Mark is described as a disciple of the famous behavioral psychologist B.F. Skinner. Skinner studied how rewards and punishment can condition behavior in humans. Mark applied that to dogs by training them with punishment and reward.

Was your brother an innovator in the dog world? I believe he was. As for cats, Mark was once quoted saying that he didn't like cats because he wants something he can control. He added, dogs are easy to change. It's people that are hard to change. See, I can't put a choke chain around them. Mark started training dogs in the 1970s and by the 1980s was a well-established canine guru.

Was your brother an innovator in the dog world? I believe he was. As for cats, Mark was once quoted saying that he didn't like cats because he wants something he can control. He added, dogs are easy to change. It's people that are hard to change. See, I can't put a choke chain around them. Mark started training dogs in the 1970s and by the 1980s was a well-established canine guru.

Mark never married during that time. Then, in the early 90s, when Mark was nearing 40, a wealthy potential client called.

Mark never married during that time. Then, in the early 90s, when Mark was nearing 40, a wealthy potential client called.

Linda Updike was the daughter of Wally Updike, one of the wealthiest businessmen in the state of Washington.

Linda Updike was the daughter of Wally Updike, one of the wealthiest businessmen in the state of Washington.