By Verna Gates

BIRMINGHAM, Alabama (Reuters) - Four people found dead on a rural Alabama road in a suspected murder-suicide were under investigation on suspicion of child sexual exploitation, investigators said.

The four bodies were found in a car on a logging road in Winston County, Alabama.

All four lived at the same address in Savannah, Tennessee, and fled after the FBI seized their computers and cameras during a search in September, Winston County Sheriff Rick Harris said on Tuesday.

"In my personal opinion, these are just four more wolves out of our world," said Harris.

The four left suicide notes proclaiming their innocence and leaving instructions for their families, Harris said.

Before shotgun blasts to the head killed them, they had purchased over-the-counter sleeping pills at a nearby store. Toxicology tests have been ordered to see they were drugged before being shot, according to Harris.

A friend in the area knew of the plan, but thought the four had been talked out of the drastic action, the sheriff said.

The bodies of Robert Samuel Hamrick, 30; Andy Keith Hunt, 37; Kevin Carey, 30, and Kristie Hamrick, 39, were discovered in a car parked at a spot commonly used by hikers.

A woman saw the car on her way to work and called police after noticing it was still there at the end of the day with the motor running, radio blaring and windshield wipers moving. A shotgun lay outside the car, according to Harris.

The dead were unrecognizable and were identified by the signatures on the suicide notes, which matched the signatures on their driver's licenses, Harris said.

"It looked like a 'Helter Skelter' Hollywood movie scene. I had 30-year veterans shaking their heads," Harris said.

Robert and Kristie Hamrick were divorced after marrying in 2002 and Hunt was Kristie Hamrick's brother. Carey was a friend, the Alabama sheriff said.

The four were under investigation on suspicion of child sexual molestation, according to Sheriff Samuel Davidson of Hardin County, Tennessee.

Hunt was the shooter and fired the fatal rounds, Harris said.

(Editing by Jane Sutton and Bob Burgdorfer)