ST. PAUL -- Police in Minnesota say a campus security guard who claimed he had been shot by a "black man in a hoodie" actually shot himself, reports CBS affiliate WCCO.

Police said they arrested 25-year-old Brent Patrick Ahlers after he admitted he accidentally shot himself on duty Tuesday night at St. Catherine University in St. Paul.

Ahlers had previously said he was shot in the shoulder by a person he confronted in a wooded area on campus, according to WCCO. The report led to a campus-wide lockdown, and dozens of officers went building-to-building searching for the "suspect."

St. Paul Police say Ahlers eventually confessed to making up the story because he brought his gun to campus and was afraid he would lose his job. Firearms are prohibited on campus.

Get Breaking News Delivered to Your Inbox

Ahlers is facing a misdemeanor charge of falsely reporting a crime.

St. Paul Police officer Mike Ernester said the false shooting report led to heightened concerns on campus.

"It had basically 1,800 students held captive in their dorm rooms," Ernester said. "It had residents of the community fearful that a suspect was on the loose and they could be victimized at any moment."

University president Becky Roloff said the suspect worked at the college for 15 months and had no previous reports of misconduct. She added that "while we are distressed and saddened that this incident occurred, we are relieved that no other members of the community were injured."