The official results of an autopsy showed that the financier Jeffrey Epstein killed himself in his Manhattan jail cell, the city’s medical examiner’s office said on Friday, determining that the cause of death was suicide by hanging.
Mr. Epstein’s death had set off a wave of unfounded conspiracy theories, as people speculated online, without evidence, that he may have been killed to keep him from providing information to prosecutors about others in his social circle, including President Trump, former President Bill Clinton and Prince Andrew of Britain.
But on Friday, the chief medical examiner in New York City, Dr. Barbara Sampson, released a terse statement saying that, after an autopsy and a “careful review of all investigative information,” she had determined the cause of Mr. Epstein’s death was “hanging” and the manner was “suicide.”
The determination came six days after Mr. Epstein, 66, was found dead in his cell at the Metropolitan Correctional Center in Manhattan, where he was awaiting trial on federal sex trafficking charges.
Guards on their morning rounds found Mr. Epstein at about 6:30 a.m. on Saturday, prison officials said. He appeared to have tied a bedsheet to the top of a set of bunk beds, then knelt toward the floor with enough force that he broke several bones in his neck, officials said.
His suicide followed an apparent attempt to kill himself in late July, and came 12 days after prison staff had recommended he be removed from suicide watch and returned to the special wing in which he was being housed.
Mr. Epstein’s death is the subject of four federal investigations, including by the Justice Department’s inspector general and the F.B.I. The attorney general, William P. Barr, said there were “serious irregularities” in how prison officials handled his supervision.
On July 23, Mr. Epstein was found on the floor of his cell with bruises on his neck and was placed in the prison’s suicide prevention program, where he was under a 24-hour watch in a special cell.
But six days later, prison officials determined he was no longer a threat to himself and returned him to a cell in a special housing unit known as 9 South. He was supposed to have been housed with a cellmate and to have been monitored every half-hour by the two guards who patrolled the wing.
The night before he was found, however, he had been left alone after his cellmate was transferred. The two employees assigned to guard him had not checked on him for about three hours before he was discovered.
Officials said the employees, who have been placed on leave, were sleeping for some or all of that time.
Mr. Epstein had pleaded not guilty and been denied bail. Prosecutors in Manhattan said he lured dozens of underage girls into giving him erotic massages and engaging in other sexual acts in the early 2000s at his mansions in New York City and Palm Beach, Fla.
The girls were paid hundreds of dollars in cash for the encounters and, once recruited, were asked to return to his homes several times, where they were abused again, the indictment against him said.
Mr. Epstein had previously avoided federal criminal charges in 2008, when he pleaded guilty to state prostitution charges in Florida in a plea agreement with federal prosecutors that resolved a similar set of allegations. He spent 13 months in a local jail, but was allowed to leave for 12 hours a day, six days a week, ostensibly for work.
The conspiracy theories surrounding Mr. Epstein’s death were fueled in part by a paucity of information from Bureau of Prison officials since his body was discovered.
The bureau issued one terse statement with little information about the circumstances of his death and has never provided information about Mr. Epstein’s earlier apparent suicide attempt.
On Monday, the federal judge in Mr. Epstein’s case, Richard M. Berman, noted the unanswered questions about the July incident. “It has never been definitively explained what the B.O.P. concluded,” Judge Berman wrote in a letter to the warden of the Metropolitan Correctional Center on Monday.
Given the lack of explanation, the high-profile nature of Mr. Epstein’s crimes and the disgraced financier’s ties to a number of prominent people, wild theories about his death spread across social media from people of disparate ideologies.
Several prominent figures in politics, media and academia, while insisting they were not conspiracy theorists, expressed skepticism that Mr. Epstein had killed himself. Mr. Trump, who has shared unfounded conspiracy theories in the past, also contributed to the frenzy, sharing a tweet with a baseless theory about Mr. Epstein and the Clintons.
Dr. Sampson, the medical examiner, said on Sunday night that her office had conducted an autopsy of Mr. Epstein but declined to release a determination about the cause of death. A city official said at the time that she wanted more information from law enforcement before releasing her determination. A private pathologist hired by Mr. Epstein’s lawyer observed the autopsy.
On Thursday, an article in The Washington Post fueled further speculation when it reported that Mr. Epstein’s autopsy showed that he had broken neck bones that could have been a sign of strangulation as well as of suicide by hanging.
But Dr. Sampson and several experts cautioned against drawing conclusions, saying the broken bones were consistent with hanging, especially in an older man.