"The morning after the Datto news broke, the Washington Free Beacon reported that the FBI has seized four State Department servers in its probe of Clinton's personal email system. Investigators want to know "how top secret material was sent to Clinton's private email by State Department aides."
In my 26 years of military service the only way to send classified info from a secure to a non-secure device was to download it to a removable device and then upload it to the non-secure device.
TS material is required to be under “two person integrity” meaning two people (with TS clearance) had to be present at all times when TS material was accessible.