A person of interest was taken into custody overnight in connection with the shooting at Brown University, officials said on Sunday.

The shooting erupted Saturday afternoon in the engineering building of the Ivy League school in Providence, Rhode Island, during final exams.

Surveillance video released by police shows the suspect, dressed in black, calmly walking away from the scene. His face is not visible and investigators said it wasn’t clear whether the suspect is a student.

Officials did not identify the suspect on Sunday.

A shelter-in-place for Brown University and the surrounding areas that was in place on Saturday has been lifted.

“However, police activity continues in areas that are still considered an active crime scene,” the university said. “Be advised that access to these areas of campus continues to be limited.”

Investigators were not immediately sure how the shooter got inside the first-floor classroom. Outer doors of the building were unlocked but rooms being used for final exams required badge access, Providence Mayor Brett Smiley said.

“In a building like that on a weekend, there are a lot of things going on,” Brown Provost Francis Doyle said on Saturday. “Study sessions, student groups meeting, there are research labs in that building. So we don’t have detailed knowledge of exactly what was happening, but we’re working with law enforcement.”

University President Christina Paxson told reporters on Saturday that all the victims, those killed and wounded, were students. 

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