Winston County Sheriff Rick Harris said Monday the four died in what appears to be a murder-suicide with a shotgun.
Harris says 29-year-old Robert S. Hamrick and his 39-year-old ex-wife, Kristi Hunt Hamrick, were under investigation for allegations of child pornography and molestation in Hardin County, Tenn.
The sheriff says they shared an address with 30-year-old Kevin Carey and 37-year-old Keith Hunt, who also were implicated.
All four were found dead Wednesday in a car on a dirt road about 100 miles south of their home in Savannah, Tenn.
Harris says it appears Keith Hunt killed the others, then himself. He was the brother of Kristi Hunt Hamrick.