He was 21, with an unremarkable background, a spotty work history and no criminal record.

He observed a girl getting on a school bus, stalked her and meticulously planned his crime. He abducted the girl, throwing her in the trunk of his car after brutally murdering her parents. He imprisoned the girl in his home, turning a radio up to drown out any possible sound when family members came to visit.

Jake Patterson's crimes are hard to wrap one's mind around.

Even for an expert in deviant criminal behavior.

"To go from a few areas of rejection ... to this extreme is very rare," said Robert Geffner. "Which is why this particular situation doesn't match most of the others we read about or hear about."

Although he lives in San Diego, Geffner was like so many transfixed by the story of 13-year-old Jayme Closs' Jan. 10 escape from Patterson's home near Gordon, Wis., after she had been held captive for 88 days.

He had more than a casual interest. Geffner is president of the Family Violence and Sexual Assault Institute in San Diego and is an adjunct professor in the California School of Professional Psychology with specialties that include violent offenders, sex offenders and emotional abuse.

In a telephone interview in the days following Patterson's arrest, Geffner said what was known about him didn't fit the patterns that emerge in criminal deviance.

"First, you don't have any contact that anybody knows of ahead of time ... which is very unusual," Geffner said. "You have a complete stranger who evidently decides for some unknown reason to attack and then goes to very extreme (measures) ... to essentially eliminate any contacts for her. Her family is basically destroyed in front of her."

Geffner made it clear that he wasn't conducting a long-distance psychological evaluation. But the behavior was so atypical, Geffner said, it would be difficult for anyone to understand.

What's known of Patterson's past also doesn't fit any patterns, Geffner said.

"At least according to the records that have been publicized, no history of violence," he said. "Normally, you would see either some type of delinquency or acting out or violence toward animals or some type of what we would call antisocial behavior."

Mental health professionals have a long way to go when it comes to predicting violent behavior, Geffner said. But the risk factors that are known - someone with a history of violence, someone with serious mental health or psychotic episodes, someone with significant trauma issues, someone who had been exposed to significant violence - don't seem to apply to what is known about Patterson.

It appears from what is known that Patterson terrorized Jayme to the point that she experienced "learned helplessness" or "learned hopelessness," Geffner said. He noted that Patterson felt confident enough to have family over for Christmas while keeping Jayme under a bed.

Those circumstances make Jayme's escape all the more remarkable, Geffner said.

Although the good news of that bold escape after Jayme survived such a horrific crime made her story a national sensation, the underlying role of violence in our society doesn't get enough consideration, Geffner said.

"We don't pay enough attention to the violence that occurs in homes and communities on a daily basis around our country," he said. "We're getting desensitized to the violence in our society, and to me that's a very dangerous road to be on."