TALLAHASSEE, Fla. — When a 20-year-old opened fire at Florida State University, terrified students barricaded doors and fled across campus from a shooting that investigators said killed two men and wounded at least six others.

By early Friday, memorials of candles and flowers dotted the campus and a schoolwide vigil had been scheduled as students and faculty tried to start healing from the shooting, which sent shock waves of fear across the campus.

“I heard some gunshots and then, you know, just blacked out after,” said Carolina Sena, a 21-year-old accounting student who was inside the student union when the shooting started. “Everyone was crying and just panicking. We were trying to barricade ourselves in a little corner in the basement, trying to protect ourselves as much as we could.”

The shooter, identified by police as Phoenix Ikner, is believed to be a Florida State student and the son of a sheriff’s deputy who opened fire with his mother’s former service weapon, investigators said. Authorities have not yet revealed a motive for the shooting, which began around lunchtime Thursday just outside the student union.

Officers quickly arrived and shot and wounded the gunman after he refused to comply with commands, said Tallahassee Police Chief Lawrence Revell.

The two men who were killed were not students, said Florida State University Police Chief Jason Trumbower, adding that he would not release additional information about the victims.

The shooter obtained access to a weapon that belongs to his mother, who has been with the sheriff’s office for over 18 years and has been a model employee, said Leon County Sheriff Walt McNeil. Police said they believed Ikner shot the victims using his mother’s former service handgun, which she had kept for personal use after the force upgraded to new weapons.

Five people who were wounded were struck by gunfire, while a sixth was hurt while trying to run away, Revell said in a statement Thursday night. They were all in fair condition, a spokesperson for Tallahassee Memorial HealthCare said.

The shooter was a long-standing member of the sheriff’s office’s youth advisory council, the sheriff said.

“He has been steeped in the Leon County Sheriff’s Office family, engaged in a number of training programs that we have,” McNeil said. “So it’s not a surprise to us that he had access to weapons.”

As of Thursday night, Ikner was in the hospital with “serious but non-life-threatening injuries,” according to Revell.