While President Trump made headlines this week for his provocative rhetoric on North Korea and the Obama administration’s nuclear deal with Iran, several major developments related to the ongoing probe of possible collusion between his associates and Russia flew quietly under the radar.

Each new disclosure about the direction and breadth of special counsel Robert Mueller’s investigation lent credence to what many legal experts have been saying since the former FBI director began hiring lawyers with expertise in corruption, foreign bribery, and white collar crime: This is serious, and some in Trump’s orbit should be worried.