A graduate student at the University of North Carolina at Chapel Hill was charged Tuesday in the murder of a faculty member who was shot and killed on campus Monday, causing an hourslong lockdown and panic.

Tailei Qi, 34, was arrested and charged with first-degree murder and having a gun on an educational property, according to county jail records.

The victim of the shooting was identified by campus police as Zijie Yan, an associate professor in the department of applied physical sciences.

“He was a beloved colleague, mentor and a friend to many on our campus and a father to two young children,” UNC Chancellor Kevin Guskiewicz said in a press conference Tuesday.

UNC Police determined Qi approached the victim directly, Police Chief Brian James said. Qi exited the building quickly after the shooting and fled on foot before being taken into custody without incident near his home.

"We're still exploring the relationship between the professor as well as the suspect," James said.

Police have not yet determined the motive of the shooting and are "looking for any information out there that may have indicated what his intentions were and why he actually did it," James said. Anyone with information should contact UNC Police.

Qi appeared in court Tuesday afternoon in an orange jumpsuit alongside a public defender and interpreter. Judge Sherri Murrell told him he could face the death penalty if convicted and a minimum of life in prison without parole for first-degree murder, and up to two years in prison for possession of a gun on campus. He will be held without bond and appear in court again Sept. 18.

His attorney didn't immediately respond to a request for comment.

What happened on the UNC campus?

Campus police received a report of shots fired at Caudill Laboratories, a chemistry building near the center of campus, shortly after 1 p.m. Monday, UNC Chief of Police Brian James said.

When they arrived at the scene, police found the faculty member shot. No one else was injured, James said.

The campus went into a roughly three-hour lockdown, and videos posted to social media show dozens of police officers responding and a helicopter flying over the campus while people fled buildings, even climbing out of windows.

Clayton Ulm, 23, a graduate student, said he was in a class of about 50 to 70 people when they were told to go into lockdown. The alarm system had gone off, but screens in the classroom had also glared with the lockdown order.

“Then there was quite a bit of panic as students were trying to figure out what to do,” Ulm told the Associated Press in a message while still in the classroom, heading into his third hour of lockdown. “Then we all started hiding beneath our chairs and under desks. Some students went and locked the doors.”

Classes at UNC Chapel Hill were canceled, just a week after the semester began. Classes will resume on Thursday, Guskiewicz said.

Beth Morocco, a public health professor who researches violence, told ABC11 she was in a faculty meeting when the alert went out.

“It’s usually a time of energy and enthusiasm, and to have something like this happen is really awful,” she told the station.

Who was Zijie Yan?

Yan was an associate professor and leader of the Yan Research Group, which said its goal was to "transcend the boundary between photonics and materials science by developing new techniques to study light-matter interactions at the nanometer scale."

"The university is in contact with Yan’s family and is providing resources and support," campus police said in a statement Tuesday.

He received his Ph.D. in materials engineering from Rensselaer Polytechnic Institute in New York and previously taught at Clarkson University. He worked at UNC since 2019, according to his biography.

"My prayers continue to be with the UNC Chapel Hill community today as the Tar Heels mourn the loss of Professor Zijie Yan, and process yesterday’s chaos and terror," North Carolina Rep. Alma Adams said. "I find strength in knowing no person, no evil, can diminish the light and liberty at our oldest public university."

Who is the suspect?

Qi is listed on the university's website, accessed by USA TODAY through internet archives, in the department of applied physical sciences. Qi's adviser is listed as Yan, the faculty member killed in the shooting Monday. The two also co-authored research papers.

Qi was a graduate student at the school, District Attorney Jeffrey Nieman confirmed to USA TODAY.

The research group's website says Qi is a Ph.D. student who joined the Yan Research Group in January 2022 and had degrees from Wuhan University in China and Louisiana State University.

“To actually have the suspect in custody gives us an opportunity to figure out the why and even the how, and also helps us to uncover a motive and really just why this happened today. Why today, why at all?” James said.

Officials didn't give a motive for the shooting as of Tuesday.

Contributing: Itzel Luna, USA TODAY; The Associated Press