Boston bombing suspect to be charged in officer's death

Boston Marathon bombings suspect Dzhokhar Tsarnaev will be tried for the murder of an MIT police officer in the frantic days after the attack, a prosecutor said Thursday.

Sean Collier, 27, was fatally shot in his patrol car April 18, 2013 -- three days after the blasts at the marathon finish line that killed three people and wounded more than 260. Tsarnaev is currently on trial for murder and other counts related to the bombings.

"We intend to move forward with criminal charges against Tsarnaev after the current federal trial is completed," Middlesex County District Attorney Marian Ryan said in a statement.

Collier was shot in his patrol car while responding to a disturbance outside a university building. Police have theorized the Tsarnaev and his brother, Tamerlan, were trying to steal Collier's gun. A county grand jury indicted Tsarnaev in that shooting months after the shooting, Ryan said.

Hours after Collier's death, early on April 19, Tamerlan Tsarnaev was killed in a shootout with police. Ryan said her office is investigating that incident, in which transit Officer Richard Donohue was wounded, and that more charges could result.

Dzhokhar Tsarnaev was found, wounded and hiding in backyard boat, hours after the shootout.

Tsarnaev, now 21, already is on trial on a 30-count federal indictment in connection with the bombings and subsequent manhunt. The trial, which began March 4, has featured gripping testimony from blast survivors -- some of whom had body parts literally blown off -- and police officers who conducted the tense manhunt.

Tsarnaev could face the death penalty if convicted of the most serious charges in federal court. He could face life in sentence if convicted of killing Collier.