(Reuters) - Two cameras that malfunctioned outside the jail cell where financier Jeffrey Epstein died as he awaited trial on sex-trafficking charges have been sent to an FBI crime lab for examination, a law enforcement source told Reuters.

Epstein’s lawyers Reid Weingarten and Martin Weinberg told U.S. District Judge Richard Berman in Manhattan on Tuesday they had doubts about the New York City chief medical examiner’s conclusion that their client killed himself.

The two cameras were within view of the Manhattan jail cell where he was found dead on Aug. 10. A source earlier told Reuters two jail guards failed to follow a procedure overnight to make separate checks on all prisoners every 30 minutes.

He had been taken off suicide watch prior to his death.

The cameras were sent to Quantico, Virginia, site of a major FBI crime lab where agents and forensic scientists analyze evidence.

The Washington Post reported on Monday that at least one camera in the hallway outside Epstein’s cell had footage that was unusable. The newspaper said there was other usable footage captured in the area.

The U.S. Justice Department declined comment. The FBI and Federal Bureau of Prisons did not respond to requests for comment. All are investigating his death. Lawyers for Epstein also did not respond to requests for comment.

Epstein, a wealthy 66-year-old money manager who once counted U.S. President Donald Trump, former President Bill Clinton and Britain’s Prince Andrew as friends, was arrested on July 6 and pleaded not guilty to sex trafficking charges involving dozens of girls as young as 14.

At Tuesday’s court hearing, 16 women said Epstein had sexually abused them, with some lamenting that his death deprived them of the opportunity to obtain justice.