Official: Attack suspect didn't show violent signs

Students were being allowed back on campus, but classes won't resume for several weeks, Acting Vice President Namsoo Woo said.

Several students were escorted by police into the school on Thursday to retrieve belongings. It was their first time in the school since Monday.

Dechen Yangdon, 27, waited nervously before two investigators took her inside. She is being hailed as a hero for intuitively locking a classroom door and turning off the lights after hearing gunshots. The shooter tried kicking in the door then fired at it. No students were injured.

Investigators who walked Yangdon inside the school shook her hand and praised her.

Asked what it was like being back inside the school, Yangdon gave a blank stare, bowed her head, grabbed her husband's hand and quickly walked away.

Choi reported from New York and Burke reported from San Francisco. Associated Press multimedia producer Jenni Sohn in New York also contributed to this report