F.B.I. officials questioned Hillary Clinton extensively about her judgment in using her private email system to discuss classified drone strikes and in allowing aides to destroy large numbers of emails, before ultimately deciding she should not face criminal charges, according to investigative documents released Friday.
In a 3½-hour interview with the Justice Department’s top counterintelligence officials in July, Mrs. Clinton defended her handling of her private email system by saying repeatedly that she deferred to the judgment of her aides, an F.B.I. summary of the interview showed.
The newly disclosed documents, while largely reinforcing what had already been known about the F.B.I. investigation, provided a number of new details about Mrs. Clinton’s use of a private email system, which has shadowed her presidential campaign for more than a year.
The F.B.I. documents revealed what appeared to be a frantic effort by an unnamed computer specialist to delete an archive of Mrs. Clinton’s emails weeks after the existence of the private server became public in March 2015.
Days after The New York Times first reported that Mrs. Clinton had used a private email system exclusively as secretary of state, the House committee investigating the 2012 attacks in Benghazi, Libya, asked that her emails be preserved and subpoenaed those that were related to the attacks.
About three weeks later, however, the unnamed specialist “had an ‘oh shit’ moment” and realized that he had not destroyed an archive of emails that was supposed to have been deleted a year earlier, according to the F.B.I. report.
The specialist then used a program known as BleachBit to delete an unknown number of emails, according to the report. Mrs. Clinton told investigators that she was unaware that the aide had deleted the emails.