Authorities are trying to determine what led to a shooting at a Veterans Affairs hospital in which a housekeeping employee suffered an ankle wound and a retired worker was taken into custody.

Police said Paul Burnside, 61, was shot in the ankle Monday in a struggle over a gun with 59-year-old Neil Moore, who left after the shooting. Moore was taken into custody at another hospital where he was seeking psychiatric treatment, police said. The revolver went off as the two fought over it in an employee break room, according to authorities.

“We don’t know how he exited,” Dayton police Chief Richard Biehl said.

Moore and Burnside apparently knew each other, but Biehl said investigators hadn’t yet determined a motive. It was not immediately known where Moore was being held or whether he will face charges.

Moore worked in housekeeping for 27 years before retiring last October, according to a statement from the hospital. Burnside also was a housekeeping aide and started at the hospital in 1998.

Authorities said three peopled witnessed the shooting. In a 911 call, an officer with the Veterans Affairs police told a dispatcher the suspected gunman was wearing a jacket with a U.S. Marine Corps emblem and that they were searching for him on the first floor. The FBI said a revolver was found later inside the suspect’s vehicle.

Moore’s sister-in-law, Stephanie Brooks, told reporters outside the family’s home in the Dayton suburb of Trotwood that they were devastated. “We’re all confused and we’re trying to find out what has happened,” she said.

Neighbors said they were shocked to hear that Moore was the suspect.

“It was surreal,” said Charles Taylor, 37, who lives across the street from Moore. “He has always seemed to be a good guy, and a role model for the neighborhood.”

Burnside’s daughter, Shirneal Burnside, 16, said outside his house Monday that her sister called to tell her about the shooting, but she had few details.

“It’s just crazy that people do such things,” she said.

The shooting, during the lunch hour in the basement of the hospital’s main building in the service and operations area, caused a lockdown at the hospital as FBI agents searched the complex.

Army veteran James Woods, of Dayton, who goes to the hospital several times a week for dialysis, was inside an adjacent building when he heard over the loudspeaker there was a lockdown. He didn’t know what was going on initially, but soon found out that there had been shooting.

“I was worried at first, but then someone said they caught the guy,” Woods said.

The hospital complex has beds for about 450 people and provides veterans with medical, mental health and nursing home care. It does not have metal detectors at its entrances, but the hospital does have its own security force.

Four years ago, an Iraq War Army veteran who had been a patient at the hospital shot himself to death at a monument to soldiers outside the facility.