Police are working to determine motive and find the gun used in fatal shooting of University of North Carolina faculty member

A suspect is in custody but police still are looking for the weapon and the motive behind the fatal shooting of a faculty member at the University of North Carolina at Chapel Hill on Monday afternoon.

Neither the victim nor the assailant has been identified after the early afternoon shooting sent the university with more than 30,000 students into lockdown for hours. The suspect was detained about 90 minutes after the gunfire interrupted activities at the school’s Caudill Laboratories, a chemistry studies building.

“We want to ensure that we gather every piece of...