At least one camera in the hallway outside the cell where authorities say registered sex offender Jeffrey Epstein hanged himself earlier this month had footage that is unusable, although other, clearer footage was captured in the area, according to three people briefed on the evidence gathered earlier this month. It was not immediately clear why some video footage outside Epstein’s cell is too flawed for investigators to use or what is visible in the usable footage. (...) The footage is considered critical to those inquiries, and the revelation of an unusable recording is yet another of the apparent failures inside the Metropolitan Correctional Center (...). It’s unclear whether the flaw in the taping affected a limited duration of the footage or whether it was a chronic problem in the beleaguered Manhattan facility. A Bureau of Prisons spokesman declined to comment, as did spokespeople for the FBI, the Justice Department and the U.S. attorney’s office in Manhattan.