(Adds background about case; byline)
By Scott Malone
BOSTON, Feb 25 (Reuters) - Formal seating of a jury and opening statements in the trial of accused Boston Marathon bomber Dzhokhar Tsarnaev are expected to begin in the middle of next week, a court official said on Wednesday.
Tsarnaev, 21, an ethnic Chechen and naturalized U.S. citizen who was a student at the University of Massachusetts in Dartmouth, is charged in federal court with killing three people and injuring 264 in the April 15, 2013, attack.
He faces the possibility of the death penalty if convicted of federal terrorism charges and other offenses.
Besides charges stemming from the marathon attack, Tsarnaev is accused of fatally shooting a police officer three days after the bombing as he and his older brother, Tamerlan, prepared to flee the Boston area. Tamerlan Tsarnaev, 26, died that night following a gun battle with police.
Jury selection began in early January, and has reached the stage that "it is anticipated that formal seating of the jury and opening statements will commence on Wednesday, March 4," a court official said in a statement.
The trial could run through June, according to the presiding judge. (Reporting by Scott Malone in Boston; Editing by Steve Gorman, Eric Walsh and Mohammad Zargham)