Martin’s 7-year-old sister, Jane, looked up to her big brother, a friend said.

Classmates said Martin told a mean knock-knock joke, always won at math games, and stuck up for friends at school.

Krystle Campbell “was one of those people who always have to be doing something for somebody,” her grandmother said.

"She loved being around people. She was a people lover, even as a little girl. She always had a lot of friends around her. She loved music, and she loved life, Krystle did. She was always bouncing and always happy,” Lillian Campbell said.

Lingzi Lu, a BU graduate student from China’s northeastern city of Shenyang, was identified as the third victim.

Lingzi Lu played piano and sometimes practiced on campus, a friend said. A former teacher described her as an “exceptionally clever [and] modest” student.