CHAPEL HILL, N.C. (WNCN) — “Please, get the message out there’s an active shooter,” a caller desperately told 911 dispatchers moments after a UNC-Chapel Hill professor was gunned down.

The call for help came in at 1:02 p.m. The caller, who told dispatchers they were inside Caudill Labs, could be heard telling others around them to close the doors and stay inside.

When the dispatcher asked the caller if they knew who the gunman was, the answer was, “I do. I know exactly who it is.”

They named Tailei Qi as the shooter and said he was still on campus with a gun. She told them he was a graduate student.

“You can look him up on our website. You can see a picture right there of him,” the caller said.

“We need immediate help. The campus needs to be locked down,” the caller urged. The caller told dispatchers there were still people walking past their building oblivious of the shooting.

Moments later, UNC would send out an alert reading, “Emergency: Armed, dangerous person on or near campus. Go inside now; avoid windows.” It prompted an hours-long lockdown of the university as police searched for the gunman. He was eventually arrested less than two miles away from campus on Williams Circle.

Dr. Zijie Yan was later identified as the victim in the shooting. He associate professor in the Department of Applied Physical Sciences and worked at UNC since 2019.

An online footprint shows Yan led a research group with Qi joined last year. He leaves behind a wife and two children.

UNC-Chapel Hill police chief Brian James told reporters earlier this week that the weapon used by Qi, which warrants said was a 9-millimeter pistol, had still not been found.

Qi was arraigned on charges of first-degree murder and bringing a weapon onto educational property. The maximum sentence for first-degree murder is the death penalty. However, District Attorney Jeff Nieman said they will not be pursuing it.