LOS ANGELES (CBSLA.com) — Victims, observers, journalists, politicians, lawmakers — they all want to know what was inside the minds of Boston Marathon bomber suspects Tamerlan and Dzhokar Tsarnaev.

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KCAL9’s Tom Wait spoke to a retired FBI Special Agent, Steve Moore, who might have some insight.

“I was very surprised that he allowed himself to be captured,” said Moore about 19-year-old Dzhokar.

Moore worked for “the Bureau” for 25 years.

He was on a squad that interrogated suspected Al Qaeda terrorists. With Tsarnaev’s capture — another question — if he survives, will he talk?

That answer, says Moore, depends. “It completely changes with different people.”

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One person Moore once questioned had just machine-gunned a group of 5-year-olds. “He was respectful but he was fully aware that I was there to get the death penalty for him.”

Moore believes the brothers became completely unhinged when their photos became public. “Once they’ve been identified, they may have been thinking, we have a short time. The clock is running until they get us. Let’s do everything we thought about doing.”

And when Dzhokar’s brother died last night the 19-year-old likely began to face a new terrifying reality, according to Moore. “When the older brother died, my guess is the younger brother had a visit to death — he got to see what was ahead of him.”

While we may never know their mental state, the younger Tsarnaev returned to a normal life after the Marathon bombings. He went to class at his college, the gym and even attended a dorm party.

In Moore’s career, he says, “I caught people for not showing up to things after a crime. He may have gone to class just to appear normal.”

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Investigators must now try to put the puzzle of the brother’s strange and horrific crimes together — if guilty, how and why did these seemingly normal young men snap? — the answers may never come from the surviving brother. Moore believes the ultimate answers will come from the duo’s computers.