(CNN) The suicide of Jeffrey Epstein is bringing attention to what employees say is a broader problem at short-staffed budget-constrained federal prisons where employees who aren't prison guards are doing guard duty and overtime shifts regularly.
Attorney General William Barr said Monday that "serious irregularities" were found at the Metropolitan Correctional Center in New York, long thought to be a well-run facility that has been used to house high-profile prisoners who require highly secure conditions.
In the case of Epstein, at least one of the two employees on duty at the time was not part of the regular detention workforce but was filling in as a guard, according to a person briefed on the matter. The person's regular position is not publicly known.
Budget cuts and hiring freezes first put in place at the beginning of the Trump administration have taken a toll at law enforcement agencies including the federal Bureau of Prisons, employees say.
After years of complaints, Barr lifted the hiring freeze in April.
But employees say the measures the bureau has had to take to live with budget restraints have taken a toll, including at the MCC.
One of those measures used is called "augmentation" and allows for workers who were hired as teachers and cooks to be trained to fill in at posts normally manned by trained detention officers.
One of the guards who was on duty during Epstein's death was filling in for regular guards.
"It's due to understaffing. It's due to not having enough correctional officers," Serene Gregg, president of the American Federation of Government Employees Local 3148, which represents employees at the MCC.
"They would be performing the functions of correctional officers," Gregg said.
The Bureau of Prisons declined to comment and referred to Barr's comments.
Epstein's attorneys, who spent as many as 12 hours a day meeting with him, had pushed the prison to move Epstein into the facility's general population, a person briefed on the matter said. One of the arguments they made was that he was doing well and that he could use an improvement in his living conditions.
Epstein's lawyers didn't respond to a request for comment.
The decision to move him from suicide watch occurred after the prison staff conducted daily psychological assessments and, according to the person briefed on the matter, determined it was safe for him to be returned to the prison's special housing unit, which is a section more restricted than general population.
When Epstein was taken off suicide watch on July 29, days after his first suicide attempt, he was returned to the facility's special housing unit, where normal protocol calls for him to be housed with a cellmate and to be checked on every 30 minutes.
Epstein's cellmate was moved out on Friday, a day before Epstein was found dead, a person briefed on the matter said. In the hours before his death was discovered, there were no checks made, the person said.
Both guards were working overtime shifts, but it's unclear whether that was mandatory. One person familiar with the matter said both employees volunteered. Union officials say that the overtime was mandatory.
Gregg claimed it's not uncommon at the MCC for employees to work 17-and 18-hour-days and are not allowed to refuse the mandatory overtimes.
"A lot of them are working mandatory overtime three or four times a week," Gregg said. "There's no one to relieve you at end of an eight-hour shift."