Marilyn Bethell, 47, of Aurora, Illinois, was found dead in a wooded area near a recreational trail in unincorporated Batavia Township on December 26, 2005. The Kane County coroner determined she had been shot in the head and ruled her death a homicide. Her body showed partial decomposition and animal disturbance, making the exact time of death difficult to determine, though investigators believe she was likely killed shortly after she went missing.

Bethell was last seen on October 30, 2005, leaving work as a counseling assistant at a substance abuse center in Hoffman Estates. On October 31 a neighbor reported seeing her black Honda Accord driven out of her garage; that same day the car was later involved in a crash and the driver fled the scene with another person in a different vehicle.

The investigation led to the arrest of 14-year-old Gareng P. Deng, who was charged with first-degree murder. Deng pleaded guilty in 2009 and received a 35-year sentence; later proceedings allowed him to withdraw that plea and he ultimately pleaded guilty again in 2015, accepting the same 35-year term. Anyone with information about Bethell, her movements in late October 2005, or the black Honda Accord is asked to come forward.