Isaac received a subpoena to testify before U.S. District Court in Delaware on Dec. 9, 2019, the documents show. One page shows what appears to be serial numbers for a laptop and hard drive taken into possession.

So far, the FBI and Delaware’s U.S. Attorney’s office have declined to publicly comment on the situation.


Fox News’ Mike Emanuel, Tom Barrabi, Gillian Turner, and Martha MacCallum contributed to this report.