Authorities in North Carolina knew the name of a suspected college campus shooter within minutes of him allegedly pulling the trigger because a 911 caller recognized him, recordings of the call show. Police say Tailei Qi, 34, killed his academic group leader, associate professor Zijie Yan, in a science building at the University of North Carolina at Chapel Hill on Monday. In portions of the 911 call released to the media, a the unidentified caller can be heard warning others of an “active shooter.” “Do you have a description of him?” the operator asks. “I know exactly who it is,” the caller responds, before spelling Qi’s name. “And he has a gun and he’s on campus.” The caller also tells the operator they “need to lock the campus down.” Qi was charged Tuesday with first-degree murder and a weapons count.