Sonoma-based developer Ken Mattson is the subject of a complaint brought to the U.S. Attorney’s Office and the SEC. The complaint was brought by Mattson’s longtime friend and business partner, Tim LeFever. LeFever is accusing Mattson of bilking he and a group of investors. That’s according to two emails LeFever sent in the past two weeks. The Press Democrat reports LeFever told the investors the IRS is also believed to be looking into the allegations.