According to NBC News, special prosecutor Robert Mueller has also been investigation both Michael Flynn Sr. and Michael Flynn Jr.
Officials who spoke to NBC News say Junior is under investigation because he works closely with his father and has been present for most of their dealings with foreign contacts including the dinner pictured above.
The inquiry into Flynn is focused at least in part on his work with his father's lobbying firm, Flynn Intel Group, three current and former officials said. It's unclear when the focus on Flynn began. [...]
Michael G. Flynn accompanied his father, for instance, on a trip to Moscow in December 2015 for the elder Michael Flynn to deliver a paid speech at a gala for the state-sponsored Russian television network RT.
If Michael Flynn Sr. did not disclose his dealings or retroactively register as foreign lobbyist until after he was caught, it seems reasonable to think his son may not have been entirely forthcoming either. The latter's history on social media, including his promotion of "Pizzagate," tells us lying comes natural to him.
One wonders if there could be a connection between the promotion of Pizzagate and other conspiracy theories on social media by Russian bots and trolls and Flynn Jr's promotion of them.