For more than four years, Shawn Hornbeck seemed to have had every chance to escape, left alone for hours to ride his bike, play video games and walk past missing-child posters showing his own age-progressed image.

But mental health experts say this troubling case is hardly so simple, and that Hornbeck was likely kept mentally shackled by terror and domination from the man accused of kidnapping him, 41-year-old Michael Devlin.

"I think it's a real mistake to judge this child. Whatever he did to this point to stay alive is to his credit," said Terri Weaver, an associate psychology professor at Saint Louis University.

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Weaver, an expert on post traumatic stress disorder, said children in such situations kick into survival mode, "doing what needs to be done to keep yourself going day-to-day."

Devlin, a 300-pound pizza parlor manager, is accused of abducting Hornbeck four years ago when the slight boy, taken as he was riding his bike, was just 11. Now a gangly 15-year-old with floppy hair and a pierced lip, he was found by surprise Friday when police acting on a tip went to Devlin's modest-two-bedroom apartment in this St. Louis suburb to rescue 13-year-old Ben Ownby, who had been snatched four days earlier on his way home from school.

Now investigators are piecing together the details of Hornbeck's captivity and Ownby's abduction, trying to discover how the man kept the boys captive in an apartment where neighbors often heard banging, shouting and arguing.

Residents in Hornbeck's hometown of Richwoods were shocked the boy could have so much contact with the outside world but remain at his captor's side — refusing to flee even as Devlin worked two jobs that forced him to leave Hornbeck and, later, Ownby, alone.

Weaver said repeated contact with outsiders can actually reinforce an abducted child's sense of helplessness.

"Over time, your safety has been threatened. You are a child. You may have been traumatized in other ways. You may feel helpless to reach out to other people," she said.

The case is reminiscent of the Elizabeth Smart kidnapping. The Salt Lake City teen was taken for nine months by a religious zealot and passed up several chances to escape.

Stephen Golding, a forensic psychologist who examined the suspect in the Smart case, said captors often establish control over their victims through fear.

"People are led to believe, through someone taking advantage of their vulnerabilities, that leaving is not an option, that things will get worse for them or will get worse for others," Golding said.

Neighbors describe Devlin as a loner with a quick temper. He obsessed over a reserved parking space at his apartment complex.

Rob Bushelle, who lives in Devlin's complex, said he made that mistake last fall. Devlin arrived in his white pickup with an adolescent boy in his passenger seat, whom Bushelle now recognizes as Hornbeck. Devlin became furious and began shouting at Bushelle, demanding he move. Bushelle refused, and Devlin called police.

While Devlin spoke with officers, Hornbeck got out of Devlin's truck and walked into the building, Bushelle said.

Devlin was raised in the St. Louis suburb of Webster Groves. His family released a statement Saturday praising law enforcement agencies for returning Ownby and Hornbeck to their families. Devlin's relatives said they prayed for Ownby's safe return when they learned last week he was kidnapped, and said "the past few days have been incredibly difficult.

"Just as we are relieved that both Ben and Shawn are now safe, we hope that Michael will be safe as the facts of his case are revealed."

Devlin's childhood neighbors told the St. Louis Post-Dispatch that Devlin was adopted and one of six children.

Sarah Sullivan described him as a quiet child in an otherwise outgoing family. He was always big for his age and avoided sports. He had a hot temper and spent a lot of time in his room, she said.

Devlin got a job at Imo's Pizza when he was in high school. He never left the pizza parlor over the years. He has no apparent criminal past, except for a pair of traffic fines, officials said.

"He's smarter than most people, so he liked to be a smart aleck," co-worker Gus Nanos told the newspaper.

"In his calmer moments, he would be an incredibly nice and thoughtful person," Nanos said.

Co-workers noticed that Devlin became more withdrawn in 2002, the year Hornbeck was abducted. That was also the year Devlin, a diabetic, had a toe amputated.

"He went from being such a teaser to a much quieter person. I felt like he had been humbled by all of his health problems," Nanos said.

Police say Devlin drove his pickup to Beaufort, Mo., Monday and kidnapped Ownby. A witness spotted his truck and its description was broadcast in an Amber Alert.

Kirkwood police officers Gary Wagster and Chris Nelson spotted the truck Thursday night outside Devlin's apartment.

"Are you seeing what I'm seeing?" Wagster asked Nelson, according to the Post-Dispatch.

A neighbor said the truck belonged to Devlin, and the officers saw him leave his apartment to empty his trash into a trash bin. They questioned Devlin in the parking lot, and he was friendly and cooperative.

His demeanor quickly changed when they pressed him for permission to search his apartment. Devlin became defensive and refused.

The officers reported the exchange to the task force in Franklin County trying to track down Ownby. Task force officers went to Devlin's apartment that night and were also refused entry.

Authorites arrested Devlin while he was at work Friday. They found Ownby in Devlin's apartment along with Hornbeck, who identified himself when they arrived.

The families of both boys have refused to comment beyond a pair of news conferences they held Saturday, during which the boys were told not to talk to reporters.

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