Case Against Tsarnaev Being Built in Collier's Death

Middlesex County prosecutors are working with federal officials in an effort to build a murder case against 19-year-old Boston Marathon bombings suspect Dzhokhar Tsarnaev in the shooting death of MIT Police Officer Sean Collier on the Cambridge campus April 18, according to Boston.com.

A spokeswoman for the Middlesex County District Attorney's office told Boston.com they believe they will have sufficient evidence to prosecute Tsarnaev for Collier's murder and should be determining the exact charges soon.

The DA's office is looking to speak to anyone who was in the area of Vassar, Main, and Ames streets in Cambridge between 10 p.m. and 10:30 p.m. April 18, Boston.com reported.

Authorities believe Tsarnaev and his brother, Tamerlan, 26, ambushed Collier, a 27-year-old Wilmington native and Somerville resident, shooting him in his police cruiser several hours after their pictures were released by the FBI as the two bombing suspects.

Tamerlan Tsarnaev was later killed after a police shootout in Watertown. After a day-long manhunt, Dzhokhar was captured in Watertown. He was charged this week in the bombing attack and could face the death penalty.

Funeral services for Collier were held in Stoneham this week, followed by a memorial service at MIT attended by Vice President Joe Biden and thousands of law enforcement Wednesday.