William and Ina Campbell were in their 80s, retired and living in Clarksville.
On January 29, 2010, a neighbor tried calling the couple several times.
When he received no answer, he used a key the couple had given him to open their door.
Once inside, he found the house ransacked. William and Ina had each been shot in the head.
Police believe the couple knew the killer or killers.
If you have any information about the deaths of William and Ina Campbell, call Clarksville Crime Stoppers at 931-645-8477. You can remain anonymous or qualify for a cash reward.