( CNN ) -- Call it knee-jerk panic or an abundance of caution . After an eyewitness reported a man with a gun on campus at American University , authorities put the Washington college on lockdown as officers swarmed out to look for him . In the end , no shots were fired , no crime committed . No one was hurt . The man turned out to be an off-duty officer from the Metropolitan Police Department . He was sitting on the bus with a woman he knew -- a student at the university . Two tense hours . But until that revelation , students already stressed over finals spent two tense hours `` sheltered in place '' -- as the school asked them to do . Warnings went out via campus e-mail within seconds of the eyewitness report : . `` AU Alert : man with gun seen on campus . Campus is in lockdown . Shelter in place . More info to follow . '' The university also sent out the warning via Twitter , and shortly thereafter , photos appeared online on the social networking service showing hundreds of students herded into safe rooms . Victoria Bera was taking a final when she saw the alert , she told the student newspaper , The Eagle . `` We were really stressed out because we were n't getting the alerts at the same time as other students , '' Bera said . `` We were able to hear the helicopters outside . '' Suspicious object . The eyewitness saw a man wearing something suspicious and called authorities . They were both riding a campus bus at the time . `` Someone saw a holster , what they believe was a holster , somebody had on them , '' Lt. Jesse Porter said . But it was enough to put the police on full steam . `` Given the culture we are in now '' police thought it was better to start with a massive response and scale back if needed , he said . `` In this time and age , people get concerned . ''
Someone reported seeing a man with a gun on an American University campus bus . But no one ever saw a gun , police said , just a holster . The university has been under scrutiny for its handling of the shooting and other recent incidents involving guns at campuses.