Details learned this week in Boston bombing probe

[April 27, 2013]  (AP) -- As the Boston Marathon bombings investigation continues, more information from authorities has emerged that clarifies some earlier reports from officials or provides more details on the suspected bombers, brothers Dzhokhar and Tamerlan Tsarnaev, and their backgrounds:

MIT OFFICER: Officer Sean Collier was shot inside in his patrol car late Thursday, April 18. Authorities initially said he was responding to a disturbance. Police now say there was no disturbance and he was in his parked car when he was shot by one of the bombing suspects.

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NO ROBBERY ATTEMPT: Officials at first said that the suspects were pursued after they robbed a convenience store, where the younger one was seen on a surveillance camera. Authorities later corrected their statement to say the suspects were tracked down after they needed to stop for gas and a driver they had carjacked fled and called police.

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GUN BATTLE: Federal officials say only one gun was recovered at the scene of a shootout with the suspects early April 20, when more than 250 rounds were fired, according to Police Commissioner Ed Davis. The elder suspect died after that exchange of gunfire, though his exact cause of death is still not known. A federal law enforcement official confirmed his brother ran over his body as he fled the scene in a car.

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FOUND IN BOAT: Federal authorities now say the suspect was found unarmed in a boat in a backyard in Watertown, raising the question of how or why authorities started shooting. Rounds of ammunition could be heard firing by the hundreds who gathered nearby.

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YOUNGER BROTHER: Dzhokhar Tsarnaev could face the death penalty after being charged with using a weapon of mass destruction to kill people and destroy property. Federal authorities say he shared information with interrogators until being read his constitutional rights.

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OLDER BROTHER: Tamerlan Tsarnaev and his mother, Zubeidat, were added to the U.S. database of suspected terrorists 18 months before the Boston explosions, two officials briefed on the situation told The Associated Press.

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NEXT TARGET: New York City Mayor Michael Bloomberg and Police Commissioner Raymond Kelly say the brothers had five pipe bombs and another pressure cooker and were heading to New York City when the man they had carjacked escaped and called police to give chase.

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PARENTS: U.S. investigators have traveled to southern Russia to question the suspects' parents. The couple says they want to come to the U.S. to see Dzhokhar and to recover Tamerlan's body but so far have not.

[Associated Press]

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