In November 2018, Solis announced that he would not seek re-election to his seat. Shortly after his retirement announcement, it was reported that Solis was secretly recording fellow alderman
Ed Burke, who had been charged with corruption. Court filings used to obtain search warrants at Solis’ home indicated that Solis had also recorded the Speaker of the
Illinois House of Representatives,
Michael Madigan. An investigation uncovered that Solis had paid himself hundreds of thousands of dollars out of his political campaign fund. Solis would also provide several days of testimony against Madigan during Madigan's trial as well. In April 2025, the acting U.S. Attorney in Chicago asked that bribery charges against Solis be dismissed, noting that his cooperation was vital in securing the convictions of both Madigan and Burke. In May 2025 prosecutors would dismiss criminal bribery charges against Solis. ==References==