Middlesex County District Attorney Marian Ryan plans to prosecute Boston Marathon bomber Dzhokhar Tsarnaev (21) for the murder of MIT police officer Sean Collier after his federal trial ends.

In a statement released on Thursday she said: “Dzhokhar Tsarnaev has been indicted by a Middlesex County Grand Jury for the murder of Sean Collier and we intend to move forward with criminal charges against Tsarnaev after the current federal trial is completed…In addition, the investigation remains active into the incident which occurred on Laurel Street in Watertown on Friday, April 19. The written investigatory report concerning the Laurel Street incident is anticipated to be completed within two months.”

A grand jury indicted Tsarnaev for Collier's murder in June 2013. The 26-year-old Collier was a Wilmington, DE native who earned a criminal justice degree from Salem State in 2009.

Following Collier's death his stepfather Joe Rogers said, “These are the bravest men and women I know.

“Every day they go out to keep us safe from the people who do evil in the world…I think we need to applaud them because one night it could be them walking down a dark alley.”

Tsarnaev could face the death penalty if he is convicted on charges of engineering the bombings, allegedly with his older brother, Tamerlan. His brother died during a shootout following the murder of Collier.

They are accused of orchestrating the double bombings on the finish line of the Boston Marathon on April 15, 2013. The attack killed three people and injured at least 264. Collier was killed on the night of April 18, 2013, during the search for the suspects.

His murder was the first of a series of crimes the brothers allegedly committed in the final 24 hours of the manhunt. The next 24 hours involved a carjacking, a shootout with police, Tamerlan's death, and the discovery of Dzhokhar, who was hiding in a boat parked behind a house in the Boston suburb of Watertown.

Dzhokhar Tsarnaev's defense lawyers claim he was under the influence of Tamerlan. They say the elder brother masterminded the attacks.

These new charges come the day after forensics experts testified at the federal trial they identified Collier’s blood on a pair of white golf gloves found in the driver’s seat floorboard of a Honda Accord that belonged Tsarnaev. The car was found abandoned on a street in Watertown after a shootout between the Tsarnaev brothers and police.

Prosecutors say Tsarnaev and his older brother shot and killed Collier in a failed attempt to steal his gun.

It is alleged that the brothers ambushed Collier while he sat in his police cruiser. He was responding to a disturbance on the MIT campus. He was shot six times. His gun was still in the holster.

The surveillance video of the Collier killing, introduced into evidence last week, does not identify whether it was Dzhokhar Tsarnarev or Tamerlan who pulled the trigger. Tsarnaev’s defense team claim it was Tamerlan who shot and killed Collier.

Prosecutors say both brothers are guilty. In the past few days they have being linking Tsarnarev to the crime, showing a video of his Honda fleeing the scene and pointing to Collier’s blood in the car.

Nathan Harman, an MIT student, testified that he saw the Collier’s door open and someone leaning in. That person, Harman testified, was Dzhokhar Tsarnaev.

This trial is expected to continue until June 2016. The prosecution is expected to wrap as early as next week, a month earlier than expected.

Earlier this month Martin Richard, the father of 8-year-old Martin who died in the bombings, testified. He told how he had to make the terrible decision to leave his son and tend to his daughter, Jane, who lost part of her leg, his wife and his other son Henry.

Judge George O’Toole has limited how much the defense can talk about Tamerlan Tsarnaev’s influence on his brother in the guilt phase. This means the defense may save most of its witnesses for the penalty phase. The jury could weigh in on Tsarnaev’s guilt sometime next month, before moving on to decide whether Tsarnaev lives or dies for his role in the bombings.

MIT police officer Sean Collier who was shot six times in his car on April 18, 2015.