OKLAHOMA CITY ? A 42-year-old mother of two working as an unarmed security officer at Texas A&M University was patrolling a vacant campus building by herself early Friday morning when she crossed paths with a convicted killer and prison escapee from Oklahoma.

Federal investigators say Tina Paulus’ quick thinking and calm demeanor helped lead to the capture of escaped convict Aaron Joseph Olsen, 39, about 6 a.m. Friday in College Station, Texas.

The U.S. Marshal’s Office in Oklahoma City tipped off campus police earlier this week that Olsen may be in the College Station area, said Deputy U.S. Marshal John Thomas.

Paulus, who had been briefed on Olsen, said she was patrolling Rudder Theater on the A&M campus when she encountered Olsen, who appeared to have been sleeping on a couch in a third-floor lobby.

“As I got to the third floor, all of a sudden, I saw someone getting up from a couch,” Paulus said in a telephone interview with The Associated Press.

Paulus said she grew suspicious when she started talking to Olsen and he gave her an alias he’d been known to use before.

Paulus, who previously served as a campus police officer before resigning to care of her children, said she never indicated to Olsen that she knew who he was and escorted him from the building.

Once outside the building, Paulus said she immediately contacted other officers and kept visual contact with Olsen until he was apprehended without incident near the university library.