Ms. Wilson could not be reached by telephone for comment, and her brother was not identified by the police.

Ultimately, Mr. Shalit's brother was identified among the dead.

"He's used to being in institutions," she said in an interview, speaking on condition that she and her brother not be identified.

His brother was identified by the law enforcement official as Darrel McKinnon, 29.

The deceased brother is identified as 26-year-old Tamerlan Tsarnaev.

Mr. Jang's older brother had originally been identified as the attacker, an identification that was later said to be a mistake.

His brother, Gregory, has been identified as a captain in the family.

The brothers were identified as Marty Dominguez, 40, and Manuel Dominguez, 28.

It was only after they were dead that the brothers were identified, the commander said.

The third brother is identified as Halfdan the Mild, a ruler of the Yngling dynasty depicted in the Heimskringla.