In a new motion [text, PDF] in the US District Court for the District of Columbia [official website] Monday, Special Counsel Robert Mueller [official website] accused Paul Manafort of using an encrypted messaging application to tamper with a witness.

According to the motion, Manafort, former chairman of President Donald Trump’s 2016 presidential campaign, and a longtime associate identified as “Person A” repeatedly sent these texts to Persons D1 and D2 “in an effort to secure materially false testimony concerning the activities of the Hapsburg group.”

“The evidence … establishes probable cause to believe that Manafort violated Section 1512(b)(1) by attempting to persuade [what the filing refers to as] Persons D1 and D2—both directly and through an intermediary—to support a materially false narrative in connection with the charges in the Superseding Indictment,” the motion states.

Manafort was charged [JURIST report] in October with conspiracy to launder money, making false statements, conspiracy against the US and other charges. Manafort filed a lawsuit [JURIST report] against the Department of Justice in January stating that the appointment of Mueller was overly broad and exceeded their authority. On May 15, Paul Manfort’s request to dismiss [JURIST report] indictments against him that arose out of Special Counsel Robert Mueller’s investigation was denied [opinion, PDF].