In a statement, Barr wrote that he was "appalled" to learn Epstein was found dead while in federal custody at the Metropolitan Correctional Center in Manhattan, and said his death "raises serious questions that must be answered."
Barr also announced an investigation would be opened in the Office of the Inspector General into the circumstances surrounding Epstein's death, in addition to the previously announced FBI investigation into the incident.
Although Epstein was hospitalized and reportedly placed on suicide watch in late July, he wasn't on it at the time of his death.
Attorney General William Barr released a statement through the Department of Justice on Saturday announcing the the Office of the Inspector General would launch an investigation into the circumstances surrounding Jeffrey Epstein's death by apparent suicide while in federal custody.
Epstein, a 66-year-old wealthy financier charged with sex trafficking of minors and conspiracy, was found unresponsive in his cell at 6:30 a.m., and was transported to a hospital where he was pronounced dead after staff "immediately" started "life-saving procedures." The death was by hanging, The New York Times reported. Epstein, who pleaded not guilty, was being held without bail while he awaited trial.
Barr said Epstein's death "raises serious questions that must be answered." The inspector general investigation is in addition to the previously announced FBI investigation into the circumstances surrounding the convicted sex offender's death.
Epstein wasn't on suicide watch at the time of his death
In late July, Epstein was also found unresponsive in his cell after another apparent suicide attempt, with marks around his neck that appeared to be self-inflicted. After a brief hospitalization, Epstein returned to his cell, where he was set to be monitored on suicide watch.
But multiple sources told NBC News that Epstein was not on suicide watch at the time of his death Saturday.
Epstein's charges stem from accusations that he ran a sex trafficking operation involving minor girls as young as 14, and had assaulted dozens of women in the process. Federal prosecutors were prepared to bring forth new evidence besides what had been collected in a Florida trial in 2007, during which Epstein and former Labor Secretary Alexander Acosta signed a controversial secret plea agreement that resulted in Epstein serving 13 months of an 18-month jail sentence.