That report came in to Washington police about 7:40 p.m. Wednesday, but spokesman Officer Hugh Carew said officers have not confirmed the report and no gunman had been found an hour later.
The search was continuing Wednesday evening until 8:20 p.m. CDT when DC police confirmed the lockdown was lifted. No injuries were reported.
The university sent tweets saying the campus in the city's Northwest district was in lockdown. It urged students to shelter in place, adding in a tweet that authorities were continuing to search for a possible armed person.