A Stephenville woman was found dead in her car Saturday, one day after her family reported her missing to authorities.

Investigators with the Erath County Sheriffís Department said they do not know how Kim Williamson, 38, died. An investigation into the cause of death is under way, according to Sheriff Tommy Bryant.

Bryant said investigators do not know if foul play was involved or if Williamson died of natural causes. They are waiting for autopsy results from the Tarrant County medical examinerís office.

Bryant said Williamsonís family filed a missing personís report with the Stephenville Police Department on Friday. On Saturday afternoon, a friend of Williamsonís, who knew she was missing, spotted her car in a bar ditch on FM 205. Williamsonís body was found inside the vehicle.

Bryant said the body was badly decomposed and had probably been there for several days.

Additional information about the case was not available at press time.