[3][5] Beginning in 2019, Yan was an associate professor in the Department of Applied Physical Sciences at the University of North Carolina at Chapel Hill, running a lab that conducted nanoparticle research with optical tweezers (lasers).

[6][17] On the afternoon of Monday August 28, 2023, a week into the fall semester at the University of North Carolina, the suspect drove to campus and went into the Caudill Labs chemistry building.

[18] According to UNC Police chief Brian James, the suspect went straight to Yan and fatally shot him, then immediately left the building and walked off campus.

[18][19][20] The Alert Carolina warning system activated at 1:03 p.m., sounding sirens across campus and sending emails and text messages ordering people to shelter indoors.

[24][25] At 2:21 p.m., a 9-1-1 caller reported someone matching the suspect's police description in the woods near their house on Williams Circle, in a residential area about two miles (3 km) north of campus.

[18][22][26] On August 29, Qi was charged with two felonies, first-degree murder and possessing a weapon on school property, and held without bail at the Orange County Jail in Hillsborough.

[27] On November 27, he had been found unfit to continue to trial due to his untreated schizophrenia and that he would be admitted to Central Regional Hospital in Butner, North Carolina for psychological treatment.

[33][34][35] In the evening, about 5,000 people attended a candlelit vigil at the Dean Smith Center, where chancellor Kevin Guskiewicz and other faculty members spoke in Yan's memory.