Court Filing References Secret Special Counsel Investigation. Here's What It Might Be

NPR: Robert Mueller knows how to keep a secret.

As reporters and lawyers for President Trump speculate about the end of the investigation into Russian interference in the 2016 election, the special counsel threw a curveball this week.

In sentencing documents for former White House national security adviser Michael Flynn, authorities reported that Flynn had offered "substantial" and "firsthand" assistance with not only the Russia probe, but also an unspecified ongoing criminal investigation — and, possibly, another matter, too.

Read article