You need to serve a 3 day notice immediately on both the ex-con son and "all unknown occupants". There are specific forms for this, and the procedure must be followed exactly or you will be bounced out of court. If you can scrape together some funds, there are lawyers who handle evictions on a flat fee basis, usually under $1,500. Just call your local bar association to obtain referrals. If you cannot even afford that much, go to library and check out a book from Nolo Press or Dummies on handling unlawful detainer cases. You can do it yourself if you have the patience and are willing to read the book. Just remember, you must follow the law to a tee or you will waste precious time and money having to do it over again.