The U.S. Marshal’s Service is investigating how a private security contractor’s gun went off in a hospital room at Northeast Georgia Medical Center while guarding a prisoner there, sending a bullet through a wall and into another patient’s room.

No one was hurt during the accidental shooting, which happened at about 8:30 a.m. Monday.

U.S. Marshal Dick Mecum said two guards employed by the private security firm MVM were guarding a prisoner that the FBI had turned over to the Marshal’s Service. Mecum declined to identify the prisoner or what charges he faced, saying only that he was arrested last week in North Georgia and was being treated for medical issues at the hospital. FBI spokesman Steve Emmett, deferring to the Marshal’s Service, also declined to identify the prisoner.

Mecum said one of the guards was apparently helping the prisoner to the bathroom when the guard tried to hand off his loaded Glock .40-caliber handgun to the other guard. The gun dropped to the floor and went off, sending a bullet through the baseboard of the wall and into another patient’s room, Mecum said.

Hospital spokeswoman Cathy Bowers said staffers informed the patient of what happened.

“We are very thankful there was no injury to anyone,” Bowers said.

The hospital has policies banning firearms and other weapons, but law enforcement officers are exempted from the rule, Bowers said.

The Gainesville Police Department investigated the incident at the request of the hospital’s security office and has ruled it an accident, Lt. Carol Martin said.

Mecum said the U.S. Justice Department asked the Marshal’s Service to make a report and provide recommendations.

“There will be a lot of people who take a look at this,” Mecum said.

Mecum said his office would have “a lot of recommendations” on the incident.

“They should not have been doing some of these things that were doing,” he said, adding that it’s a nurse’s job, not a guard’s, to help a prisoner to the bathroom.

The prisoner remained at the hospital Tuesday. Asked if the same two people were guarding him, Mecum said, “I doubt it.”

Mecum said MVM is contracted to work some hospital guard duties for the federal government because the Marshal’s Service “doesn’t have the manpower.”

A message left for an MVM executive at the company’s Ashburn, Va., headquarters was not immediately returned Tuesday.