Updated at 5:18p.m. ET

Two correctional officers who were assigned to guard Jeffrey Epstein on the night he died in his cell have been indicted for allegedly ignoring more than 75 mandatory checks on the wealthy financier then fabricating records to cover it up.

Federal authorities charged Michael Thomas and Tova Noel with multiple counts of falsifying records and conspiracy. The two worked as guards at the Metropolitan Correctional Center, a federal facility in Manhattan that is mostly used for defendants awaiting trial.

At a court appearance on Tuesday, Thomas and Noel pleaded not guilty and a judge released each of them on a $100,000 bond.

The indictment provides the first official account of what happened in the hours before Epstein's death.

According to video surveillance footage obtained by prosecutors, Epstein was in his cell unobserved for eight hours before he was found dead. The unit he was in requires that all inmates be accounted for twice an hour.

Prosecutors say that while working an overnight shift, Thomas and Noel, the only two officers assigned to Epstein's wing, neglected to check on him.

Instead, Thomas and Noel sat at their desks and browsed the Internet for furniture, motorcycle sales and sports news instead of monitoring Epstein in his cell, some 15 feet away in the Special Housing Unit, according to the indictment.

Authorities said for about two hours during their shift, footage shows that the two guards were apparently sleeping.

It was only when inmates' breakfast was to be served around 6:30 a.m. on Aug. 10 that Thomas and Noel entered Epstein's unit.

"Epstein hung himself," Noel told her boss, according to the indictment.

"We messed up," Thomas said to the same supervisor, the document states.

U.S. Attorney Geoffrey Berman said the two had signed more than 75 separate 30-minute round entries falsely stating that they were monitoring Epstein.

"They repeatedly failed to conduct mandated checks on inmates and lied on official forms to hide their dereliction," Berman said.

Prosecutors said security footage confirmed that nobody went into the section of the jail housing Epstein before he died, undercutting conspiracy theories that someone else was responsible for his death.

Epstein's cell mate had been transferred, leaving Epstein alone in his unit. Jail worker union officials said it was unusual to have a prisoner in this section of the jail alone in a cell, saying that had someone been housed with Epstein, the episode may have been prevented.

In response to the indictment, Bureau of Prisons Director Kathleen Hawk Sawyer issued a statement saying her agency takes any allegations of misconduct seriously.

"I am committed to this agency and am confident we will restore the public's trust in us," Sawyer said.

During a Senate Judiciary Committee on Tuesday, Sawyer told lawmakers there is no evidence to suggest Epstein died any way other than suicide.

Epstein, 66, the wealthy financier who faced sex-trafficking charges at the time of his death, was awaiting trial in a case that, if he was convicted, could have resulted in a decades-long prison sentence.

The New York City medical examiner said in August that an autopsy showed that Epstein had hanged himself in his cell, a conclusion that has been rejected by both conspiracy theorists and members of Epstein's family, who have claimed his death was a homicide and hired a private forensic pathologist to probe the incident.

There were warning signs that Epstein was a high-risk inmate. In July, guards found Epstein unconscious and with bruises on his neck. After that, Epstein was placed on suicide watch for 24 hours then transferred to a hospital ward for less than a week. He then returned to a special detention unit where inmates receive extra supervision, including being checked in on once every 30 minutes. Less than two weeks later, Epstein was found dead.

Before his death, Epstein had pleaded not guilty in a case in which authorities said he "enticed and recruited" girls to visit his mansion in Manhattan and his estate in Palm Beach, Fla., to sexually abuse them.

Prosecutors said he paid the girls hundreds of dollars in cash for their silence and coaxed them into finding him other victims. The girls, as young as 14 years old, were brought to his properties ostensibly to provide Epstein massages, but he would escalate the encounters by making unwanted physical contact that would ultimately end in sexual abuse, prosecutors wrote in a federal indictment filed in July that involved allegations stretching back to the early 2000s.

Attorney General Bill Barr said shortly after Epstein's death that he was "appalled" that such a high-profile defendant was not properly guarded in a federal facility. Barr said the Justice Department, the FBI and other authorities have launched inquiries to get to the bottom of what led to Epstein's dying in a jail cell.

Jose Rojas, an official with the union that represents Federal Bureau of Prisons officers, said in an interview with NPR that the two guards are being scapegoated for much deeper systemic problems dealing with the chronic understaffing of federal detention facilities.

"The emphasis should be on the conditions that caused the shortage of staff. And then who made the decision to take him off suicide watch? And who made the decision to leave him in the cell alone?" Rojas said.

He said the facility that Epstein was housed in was not operating with a full staff, and officers like the two charged on Tuesday worked mandatory overtime.

"If the DOJ wants to blame someone, they should look in the mirror," Rojas said. "There is a crisis in our agency. Not just in Manhattan, but throughout the Bureau. We are short of staff."

NPR's Ryan Lucas and WNYC's Erin Woo contributed to this report. contributed to this story

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