Officials seek to prosecute Tsarnaev in Mass.

Middlesex County prosecutors want to arraign Dzhokhar Tsarnaev on charges that he murdered MIT officer Sean Collier in Cambridge.FBI/AP

WOBURN — As accused Boston Marathon bomber Dzhokhar Tsarnaev awaits trial on federal terrorism charges, local authorities are seeking to prosecute him in state court in the killing of MIT police Officer Sean Collier and a shootout with Watertown police officers.

Authorities in Middlesex County have obtained a warrant for Tsarnaev, who is being held in federal prison, so they can pursue murder charges against him after his federal trial is over.

In a brief hearing Monday, Assistant District Attorney Adrienne Lynch said prosecutors intend to bring Tsarnaev to trial in state court.

Tsarnaev, 20, was indicted in June by a Middlesex grand jury in Collier’s death on April 18, three days after the Marathon bombings. Tsarnaev is also charged with four counts of armed assault with intent to murder, among a host of other charges.

“We believe it’s very important for the defendant to stand trial in this county,” said District Attorney Marian T. Ryan.

Ryan said that it is not unusual for state prosecutors to file charges, even as a federal prosecution is pending, and that the broad federal indictment against Tsarnaev does not specifically charge him with Collier’s murder or the Watertown gunfight. However, those allegations are included in the federal indictment.

Allen Collier, Sean Collier’s father, said he was pleased that Tsarnaev will face state murder charges, and he praised prosecutors.

“I can sense their commitment to prosecuting this individual for my son,” he said. “I couldn’t be happier.”

Ryan’s office told Collier last week that it planned to pursue the charges, he said.

“I think they owe it to me and the other victims’ families,” he said.

Collier, who lives in New Hampshire, said he remains grief-stricken by his son’s death, six months later. “I’m hanging in there,” he said. “But I have a long road back.”

Federal authorities said they expect Tsarnaev will not be available to be arraigned in the state case until the federal proceedings are completed. A trial date in the federal case has not been set.

Tsarnaev faces federal charges of planting the bombs that exploded near the finish line of the Boston Marathon April 15, killing three spectators and wounding 260 others. He has pleaded not guilty to the charges, which carry the possibility of the death penalty.

The federal indictment handed down in June alleges that Tsarnaev and his older brother, Tamerlan, who was killed in the Watertown gunfight, shot Collier and tried to steal his service weapon. It also alleged that they used several explosive devices against police in Watertown.

But the allegations are part of a sweeping indictment that local prosecutors said does not focus on the shooting of Collier.

“This is the killing of a police officer in the city of Cambridge,” said Rosanna Cavallaro, a law professor at Suffolk University. “That’s a very personal loss for a particular community. Nobody wants that to go unpunished by the immediate community.”

Ryan’s decision stands in contrast to Suffolk District Attorney Daniel F. Conley, who said in June that federal court was the “most appropriate” place to prosecute Tsarnaev and that state charges for the crimes that occurred in Boston would be redundant.

“In the absence of some major change in the current posture of this case, state-level indictments for crimes in Boston would only drag out the process that would already be grueling for victims, their families, and the city,” he said.

Daniel Medwed, a law professor at Northeastern University, said that dual prosecutions are relatively rare and typically involve high-profile cases that spark public outcry, such as in the case of the Washington, D.C., snipers.

If Tsarnaev is convicted on the federal charges and sentenced to death or life in prison, a state case would be largely symbolic, Medwed said. But even then, a second prosecution can be seen as helping “avenge an injustice,” he said.

“Prosecutors certainly have good grounds for proceeding,” he said.

The investigation into the Watertown shootout is continuing, prosecutors say. Given the “number of weapons involved and the amount of firepower expended during the exchange,” the investigation is expected to take several more months.

Tsarnaev’s lawyer did not attend Monday’s hearing and later declined to comment.

Last week, his legal team asked a federal judge to ease restrictions against him in prison, saying they have unduly limited communication with his legal team.

Tsarnaev has no access to media and cannot speak with other inmates. The special restrictions that have been placed on him in prison also limit what lawyers can communicate with him and what information they can share.

US Attorney General Eric Holder, who is considering whether to seek the death penalty against Tsarnaev, has said the measures are necessary to prevent him from “conspiring to commit additional criminal activity.”