It turned out that Keilar’s assumption was accurate. The 31,830 personal emails that Keilar asked about were deleted “sometime between March 25-31, 2015,” according to the FBI. That was about three weeks
after Clinton received a House subpoena on March 4, 2015.
As the FBI explains,
Cheryl Mills, Clinton’s former chief of staff, and
David Kendall, Clinton’s lawyer, oversaw the process of sorting the work-related emails from the personal emails.
Heather Samuelson, a lawyer who worked on Clinton’s 2008 presidential campaign, undertook the review to identify work-related emails and reported to Mills and Kendall.
In December 2014, after the work-related emails were preserved, Mills told Platte River Networks – which at the time was managing Clinton’s private server – that Clinton “decided she no longer needed access to any of her e-mails older than 60 days.” Mills instructed the PRN employee — who was not identified — “to modify the e-mail retention policy” on Clinton’s server “to reflect this change,” the FBI said.
But the PRN employee mistakenly did not make the retention-policy change and did not delete the old emails until sometime between March 25 and March 31, even though Mills had sent PRN an email on March 9 that mentioned the committee’s request to preserve emails.
The PRN employee who deleted the emails was a recipient of Mills’ message. However, the employee told the FBI that “he had an ‘oh shit’ moment and sometime between March 25-31, 2015 deleted the Clinton archive mailbox from the PRN server and used BleachBit to delete the exported .PST files he had created on the server containing Clinton’s e-mails.”