Boca
Governor
Sergey I. Kislyak, the Russian ambassador to the United States, arrived at President Trump’s address to Congress.
Just last Tuesday night Ambassador Kislyak attended President Trump’s speech to a Joint Session of congress. The Russian ambassador was noted in numerous conversations with Senate Democrats and was seated on the Democrat side of the venue.
Apparently, Kislyak is a regular visitor to the Capitol as noted in this tweet reply from Brit Hume:

(link)
Worth noting that Senator Dianne Feinstein is the ranking member of the Senate Intelligence Committee and one of the key CIA and intelligence community oversight members on the exclusive Gang of Eight:

Intelligence Oversight Gang of Eight