This seems to me to be a very simple issue. It is not a civil matter as there was never a landlord tenant relationship created. The owner asked a friend to watch his residence, absent a written contract that empowered him to lease the property, the friend had no legal right to lease the property through either a written or verbal agreement. As such, the lovely couple is committing criminal trespass and I would have them escorted from the property by a member of the Sheriff's Department after signing a warrant for criminal trespass, burglary 3rd, and probably criminal mischief as I'm sure the home was significantly damaged. This sounds to me like a Sheriff's Department that didn't want to get involved and gave the owner the standard line that its a civil issue so they don't have to deal with it.