BOSTON — As jury selection resumed Tuesday in the highly anticipated terror trial of Boston Marathon bombing suspect Dzhokhar Tsarnaev, the judge appeared to find what until now has been in scarce supply: prospective jurors who say they can be impartial.

Tsarnaev is charged with 30 federal counts in the April 15, 2013, bombings and in the killing days later of an MIT police officer. Three people died and more than 260 were injured when twin bombs exploded near the marathon finish line.

Tsarnaev, 21, could face the death penalty if convicted of any of 17 capital charges against him.

Last week, U.S. District Judge George O’Toole Jr. began individually questioning people who could become jurors. On Tuesday, at least four people questioned said they either had no preconceived opinions on Tsarnaev’s guilt, or if they did, they could put them aside and listen to the evidence before reaching decisions on guilt or punishment, whether life in prison or the death penalty.

One woman, a teacher, said “You’re supposed to assume someone is innocent until they’re proven guilty,” in response to questions from O’Toole.

Another woman, who works in the billing office of the Massachusetts General Hospital physicians’ organization, said she hasn’t formed an opinion on Tsarnaev’s guilt or innocence and would be able to consider both possible sentences if Tsarnaev is convicted.

“I do believe in the justice system and I believe it’s up to the justice system to make that determination,” she said.

When asked by defense lawyer David Bruck about her reaction when she received a jury summons and later realized she could be asked to serve on the jury, she said: “I looked at it as my duty and even as a privilege should I be asked to be a part of this.”