New Delhi, Sept. 11 -- Police say the gunman who fatally shot conservative activist Charlie Kirk during a debate event at Utah Valley University "appears to be of college age" and managed to blend in with the student population before opening fire.

According to law enforcement officials cited by the Associated Press, the suspect was able to move unnoticed among students and attendees before positioning himself on a nearby rooftop. From there, he fired a single fatal shot at Kirk, 31, as the activist spoke inside the university auditorium on Tuesday night.

Investigators confirmed they recovered a high-powered rifle at the scene, believed to be the weapon used in the attack. Officials have not said whether it was abandoned by the gunman o...