Terry and Darleen Anderson were found bludgeoned to death in there seven years ago on October 21 but police still do not know who killed them.
Lt. Cindy Kilgore says because of the nature of their deaths the killer is likely someone they knew.
The family has offered a $20,000 reward. They and the community will hold their annual memorial service on Sunday at 1 p.m. at their grave sites in the Mongo Community Cemetery on State Road 3 North. Terry's eldest daughter will be speaking. It will be held rain or shine.