Attorney General William Barr said Monday that there were "serious irregularities" at the federal jail where Jeffrey Epstein took his own life as he awaited trial on charges he sexually abused underage girls.

The 66-year-old financier was found Saturday morning in his cell at the chronically short-staffed Metropolitan Correctional Center, in a unit known for holding notorious prisoners under extremely tight security.

"I was appalled, and indeed the whole department was, and frankly angry to learn of the MCC's failure to adequately secure this prisoner," Barr said at a police conference in New Orleans. "We are now learning of serious irregularities at this facility that are deeply concerning and demand a thorough investigation. The FBI and the office of inspector general are doing just that."

He added: "We will get to the bottom of what happened and there will be accountability."