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Potential psychological explanations behind bombings

Pictured at left, Marathon bombing suspects Dzhokhar and Tamerlan Tsarnaev. At right: Lee Boyd Malvo saw John Allen Muhammad as a father figure. There are some similarities between the Washington, D.C., snipers and the Tsarnaev brothers.

Left: Bob Leonard/AP; Right: Sheila Tezano/Polaris/AP

Pictured at left, Marathon bombing suspects Dzhokhar and Tamerlan Tsarnaev. At right: Lee Boyd Malvo saw John Allen Muhammad as a father figure. There are some similarities between the Washington, D.C., snipers and the Tsarnaev brothers.

A teenage immigrant with intellectual promise heads out on a sunny day into the streets of a large American city and decides to murder as many innocent strangers as he can. He’s in the company of an older man who has taken the place of his father, who has long been away in a distant country.

The teen is Lee Boyd Malvo, who at age 17 killed 10 people in the 2002 Washington, D.C.-area sniper attacks, but the description also fits the still-developing profile of Boston Marathon bombing suspect Dzhokhar Tsarnaev, whose father left their Cambridge home for Russia in 2010.

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The psychological makeup of 19-year-old Tsarnaev, who is accused of setting off two pressure-cooker explosives with his 26-year-old brother, remains unknown. But forensic psychologists say there are a number of mental health conditions that could cause a young man — even one who is intelligent and seemingly well adjusted, as some acquaintances have described Tsarnaev — to fall under the malicious influence of a father figure.

They might help explain what would drive a well-liked marine biology student to allegedly carry out a terrorist attack.

Ruslan Tsarni, Tsarnaev’s uncle, told reporters last week that he does not believe the 19-year-old could have masterminded the bombing plot. “He’s been absolutely wasted by his older brother. I mean, he used him. He used him for whatever he’s done.”

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But Tsarni was just speculating, since a family fight had, for some time, left him estranged from his nephews, including Tamerlan, the older of the two brothers who had become radicalized in recent years and died in a shoot-out with police last week. Severed family ties, his parents’ divorce, and their absence — his mother has been living in Russia since last year — may have driven Dzhokhar even closer to his brother and led him to become an unquestioning partner in his violent plans.

“Immigrants often rely on a supportive network of family and friends to help them avoid the loneliness,” said Carmeta Albarus, a forensic social worker who co-wrote “The Making of Lee Boyd Malvo’’ based on her psychological analysis and meetings with Malvo during his criminal trial. “I think it’s significant that the older brother said he had not one American friend, an emptiness that can be so easy to fill by attaching yourself to some kind of cause.”

Malvo, a Jamaican immigrant, developed an attachment disorder after he was abandoned at age 5 by his father and raised by an abusive mother; he considered 41-year-old John Allen Muhammad, the other D.C. sniper, to be his father and even initially tried to take full responsibility for all the shootings. It is unlikely that Dzhokhar Tsarnaev had the same attachment disorder, because it usually forms in toddlers or preschoolers who feel abandoned by their parents, said Jonathan Mack, a New Jersey-based criminal psychologist who co-authored the book with Albarus. But he added that it is possible Dzhokhar was “brainwashed by his brother, the way Malvo was brainwashed by Muhammed.”

That can only be ascertained by conducting a mental health assessment, which would include questioning Tsarnaev along with his teachers, family, and close friends, as well as neuropsychological testing to evaluate his memory, motor function, personality, and other cognitive skills. Tsarnaev’s lawyers will probably ask for this, Mack said, because any mental deficits they uncover could be used to argue for reducing the charges or avoiding the death penalty.

Any psychological evaluation should also include a close examination of Tamerlan Tsarnaev’s history and behavior to determine whether he had psychiatric problems that may have driven him to commit murder. “There’s something called shared paranoid disorder where one person in a close relationship has delusions and eventually pulls the other one into this delusional system,” said Dr. Harold Bursztajn, a psychiatrist and cofounder of the psychiatry and law program at Harvard Medical School.

Usually, the more dominant person in the relationship develops the paranoia or delusions first and influences the weaker one to have the same twisted thoughts.

“Is this something that happened in this case? I don’t know, but I think it’s an avenue to explore,” Bursztajn said.

Tamerlan Tsarnaev’s purported religious extremism, loneliness, and hatred for the United States may have been accompanied by paranoid delusions that made it seem morally justifiable to kill innocent bystanders, Bursztajn said. “If his younger brother had hero worship, he may have taken on this paranoia as well,” he said.

Shared paranoid disorder might also explain why the two brothers did not initially plan for a quick getaway after the bombing. “They might have fantasized that God would take care of them,” Bursztajn said, and enable them to escape being identified as the bombers. Or they might simply have been careless in their planning.

The psychiatric condition, however, is uncommon, and a far more plausible scenario is that the brothers were emboldened by each other.

“They may believe that murder is wrong, but their sense of allegiance and loyalty to each other or the group may supersede that sense of right and wrong,” said James Alan Fox, a criminology professor at Northeastern University.

“Awful crimes may be committed just for the sake of a perverted kind of bonding,” Fox said. Criminals often compartmentalize, dividing the world into those they care about and everyone else.

And just as some men who commit group rape would never rape someone on their own, some people only kill in pairs. One brother may have been looking for his younger brother’s admiration, while the other was looking for his older brother’s approval.

“I think they brought out the worst in each other,” Fox said. “I’m not sure either would have committed murder on his own.”

Deborah Kotz can be reached at dkotz@globe.com. Follow her on Twitter @debkotz2.
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