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FBI and Customs and Border Protection agents were spotted on Monday at accused sex trafficker Jeffrey Epstein's house in the U.S. Virgin Islands, ABC News reports, and people with knowledge of the matter say they're looking for evidence of Epstein's inner circle.

Investigators were focusing on finding documents, videos, photographs, and computers at the home, which is on a private, 70-acre island. Epstein, 66, was found dead Saturday morning inside his Manhattan jail cell, of an apparent suicide. Last month, he was discovered semiconscious with bruises around his neck, and was placed on suicide watch, but people familiar with the matter told ABC News he was taken off about a week later at the urging of his defense lawyers.

Epstein was detained at the Metropolitan Correctional Center, and was supposed to be checked on by guards every 30 minutes. One of the people on duty at the time of Epstein's death was not a full-fledged correctional officer, prison and law enforcement officials told The New York Times, and neither one had checked on him for several hours before he was found. It is unclear what position the one employee usually worked. Union officials have long complained that there is a staffing shortage at the facility, due to a federal hiring freeze.