BOSTON — Prosecutors urged a federal appeals court Tuesday to reject a bid to move the trial of Boston Marathon bombing suspect Dzhokhar Tsarnaev out of Massachusetts, arguing that more than 50 fair and impartial jurors have already been found.

In a written filing with the 1st U.S. Circuit Court of Appeals, prosecutors noted that as of Friday, Judge George O’Toole Jr. had already qualified 54 people to serve as jurors. Of those, 63 percent indicated they have not formed an opinion that Tsarnaev is guilty and 37 percent indicated they could set aside their opinions and be impartial, prosecutors said.

Tsarnaev, 21, faces the possibility of the death penalty if convicted of carrying out the 2013 bombing. Three people were killed and more than 260 were injured when twin bombs exploded near the finish line.

Tsarnaev’s lawyers say he cannot receive a fair trial in Massachusetts because too many people believe he’s guilty and have personal connections to the marathon or bombings. The 1st Circuit Court has agreed to hear arguments Thursday on the defense request to move the trial.

Individual questioning of prospective jurors began Jan. 15.

O’Toole said 54 out of the 193 potential jurors questioned through Friday had been “provisionally qualified,” meaning they will move onto the next round of jury selection. Once 70 people have been qualified, prosecutors and Tsarnaev’s lawyers will be allowed to eliminate 23 people each for strategic reasons. A panel of 12 jurors and six alternates will be chosen.

On Tuesday, as 13 more people were questioned individually, the problem of personal connections cited by Tsarnaev’s lawyers was evident.

One man was told he could leave after he said he was asked to set up a command center at the hospital he works at when authorities were preparing to raid Tsarnaev’s dorm room at the University of Massachusetts-Dartmouth and an apartment complex where some of his friends lived. .

The man said he had formed an opinion that Tsarnaev is guilty and acknowledged that his views are “slightly tainted” by his experience.