It will likely take weeks to seat an impartial jury in the Boston bombing trial of Dzhokhar Tsarnaev.

BOSTON — Jury selection began Monday in the Boston Marathon bombing trial, where a panel of 12 ultimately will gather in a federal courthouse under tight security to determine whether suspect Dzhokhar Tsarnaev is guilty and should be executed.

Judge George O’Toole said the trial will begin Jan. 26 and could take three or four months to complete. He earlier denied a defense request to move the trial out of Boston.

Tsarnaev, flanked by his attorneys, sat at the defense table wearing a dark sweater and khaki trousers. He sometimes gazed at the potential jurors, other times peering at O’Toole.

The explosion of two bombs, near the finish line of the 2013 Boston Marathon, was the largest act of terrorism in Boston’s history. The attack, on April 15, left three people dead, injured more than 260 and led to at least 16 people having limbs amputated. The suspects were identified three days later as Chechen brothers Tsarnaev, now 21, and his brother Tamerlan Tsarnaev, 26.

As the manhunt unfolded, prosecutors say the suspects allegedly killed a Massachusetts Institute of Technology policeman, carjacked an SUV, and were involved in a shootout with police. Tamerlan Tsarnaev was killed. Dzhokhar, who was wounded, was later found hiding in a backyard boat in nearby Watertown, Mass.

Massachusetts outlawed the death penalty in 1984, and no one has been executed in the state since 1947. But Tsarnaev could face death because he’s being tried in federal court instead of state court.

More than 1,000 residents of eastern Massachusetts are on a list of potential jurors. A litany of queries boils down to two essentials: Can you be fair? Can you impose the death penalty if conditions are met?

A 2013 Boston Globe poll found just 33% of Bostonians believe Tsarnaev should get the death penalty if he’s convicted. Polls from the University of Massachusetts-Amherst found more support statewide: In 2013 and again in 2014, 59% of respondents said Tsarnaev should get the death penalty if he is found guilty.

“I have real concerns that no matter who sits on that jury, they have been impacted in some way by the events of the marathon bombings,” said Michael Coyne, dean of the Massachusetts School of Law in Andover, Mass. “We hope that, at least in the second phase, we get someone to look at the factors objectively.”

Contributing: Associated Press