An Ohio State University janitor who shot two supervisors, one fatally, and then killed himself had complained that he was being treated unfairly, though records show he slept on the job and was late to work during his probation.

Nathaniel Brown was days away from losing his job when he opened fire with two handguns early Tuesday in a maintenance building at the largest university in the United States, police said. No students were hurt.

Brown, 51, had a criminal history that included serving about five years in prison on a charge of receiving stolen property, records show. He lied about it on his job application, and it wasn’t immediately clear whether Ohio State had completed a background check on him.

Ohio State released documents from Brown’s personnel file showing that supervisors complained he was tardy, slept on the job and had problems following instructions. The university sent him a letter March 2 informing him that his employment was to end Saturday.

Brown had been scheduled to work his normal third shift Tuesday, campus Police Chief Paul Denton said. Brown arrived for work dressed in dark clothing, wearing a hooded sweat shirt and a backpack. Police didn’t say what was in the backpack. About a half—dozen other employees were in the building when the shooting began about 3:30 a.m.

Denton called the shooting work—related but didn’t describe a motive.

Police tactical units surrounded the building and found Brown with a self-inflicted gunshot wound in a garage bay, Denton said. He was pronounced dead at a campus hospital hours later.

One of the victims, building services manager Larry Wallington, 48, died at the scene. The other, shift leader Henry Butler, 60, was in stable condition at Ohio State University Medical Center, officials said.

Mr. Butler wrote a letter February 11 recommending that Brown be terminated, according records released by the university. Even though colleagues had made a special effort to help Brown, he was not improving, the letter said.

Brown was released from prison in 1984, records show. The case file had been archived, and more information on the crime wasn’t immediately available, prisons spokeswoman Julie Walburn said.

On his job application, Brown checked “no” when asked whether he had ever been convicted of a felony or misdemeanor. A letter from Ohio State offering him the job said it was contingent on a satisfactory criminal background check.

Classes went on as scheduled Tuesday. More than 55,000 students attend the main campus in Columbus. The maintenance building is next to a power plant and across the street from Ohio Stadium, home to the university’s football team.

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