On May 29th the govt. offered Maria Butina a proffer.
The status of any negotiations is unknown.
https://rapidcityjournal.com/proposed-proffer-agreement-for-maria-butina/pdf_a7064a20-7243-53f1-a934-ec9b48878210.html
https://rapidcityjournal.com/news/local/accused-russian-agent-butina-seeks-benefit-from-cooperation-in-sd/article_4ab7814d-b896-526f-b370-e31bbc4ca2a0.html
The Rapid City Journal obtained a copy of the letter Tuesday from the law firm of Butinas attorney. The letter is dated May 29, and it consists of a proposed proffer agreement from U.S. Attorney for South Dakota Ron Parsons Jr. and Assistant U.S. Attorney Jeff Clapper.
A proffer agreement allows a person to give information to prosecutors subject to ground rules established in advance. A proposed ground rule in the letter to Butinas attorney says, No statements made by your client or other information provided by her during proffer will be used directly against her in any criminal proceeding.
A proffer agreement is not a plea bargain or a promise of immunity, but it can lead to them.
The letter says it was sent in the hope that Butina may be willing to make a proffer of possible information and testimony regarding her knowledge of the illegal activities of others. The others are not named in the letter, but widespread media speculation has focused on Paul Erickson, a 56-year-old Sioux Falls man with connections to Butina.