The details also involve two unidentified Americans, one who Butina first contacted in Moscow around 2013, the other who was part of efforts to gather support for Russia within political circles in 2016 and 2017.
Much of the evidence came from documents, emails, and Twitter direct messages on Butina's laptop, which was seized by authorities during the investigation.
But the FBI affidavit also seems to indicate that investigators have emails from one American linked to Butina - identified only as "U.S. Person 1."
"I've been involved in security a VERY private line of communication between the Kremlin and key POLITICAL PARTY 1 leaders through, of all conduits, the [GUN RIGHTS ORGANIZATION]," the communication read.
The FBI affidavit offers a variety of efforts to curry favor with Americans, at the National Prayer Breakfast, Russian-American "friendship" dinners, attending annual meetings of a national gun rights organization, and other political gatherings.
Butina's work evidently also included an instance in 2015, when Butina was able to ask a question of President Trump at the "FreedomFest," where Mr. Trump - the candidate - assured his audience that he wanted better relations with Moscow.
"Putin has no respect for President Obama," Mr. Trump tells Butina, in this exchange.
While the charge against Butina was not brought by Special Counsel Robert Mueller's office, the details of the inquiry dovetail with that investigation of illegal influence in the 2016 election, a probe which President Trump on Monday again labeled a 'witch hunt.'