MERCED (CBS/AP) — Students at the University of California, Merced have returned to classes several days after a student stabbed four people before being killed by police.

KFSN reports Tuesday that one victim remains in the hospital. She suffered a collapsed lung after being stabbed in the chest and back. Campus spokeswoman Brenda Ortiz says the university has been told she will make a full recovery.

Meanwhile, the investigation continues into the freshman accused of trying to kill his classmates. The attacker, 18-year-old Faisal Mohammad of Santa Clara, died after being shot by police. Authorities believe he was angry about being booted from a study group, but they are still uncovering new evidence.

Merced County Sheriff Vern Warnke says the FBI is assisting the campus police department in the investigation after new information was revealed Saturday. He declined to elaborate.

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