A Sonoma Valley Developer who is being investigated by the FBI is possibly in more trouble. The Press Democrat reports that Ken Mattson and his wife, Stacy, are being accused of illegally removing items from a building they had just sold to tech entrepreneur Chris Fanini. The Mattsons reportedly removed items from Sonoma’s Best market and deli this past Sunday morning before deputies arrived and ordered them to return the items. It is now considered a civil matter. This comes as Ken Mattson is under FBI investigation, accused of fraud by his long time business partner, Tim LeFever. Mattson is also being sued by a former investor out of Brentwood.