A former federal prosecutor who writes about the ongoing probe into the Trump campaign’s ties to Russia on Monday filed paperwork signaling he will run for Illinois attorney general as a Democrat.Renato T. Mariotti, a partner at Thompson Coburn LLP, filed paperwork with the State Board of Elections establishing the Citizens for Renato political committee. The committee would back his potential run for attorney general.In an interview, Mariotti declined to confirm his run for attorney general, saying an announcement …