Ninety-one-year-old Larry Boyette was shot and stabbed in his home last June. Deputies say they have interviewed almost 600 people so far, but they still do not have a suspect.
In a behavioral profile released Thursday, deputies say the killer is probably a white man in his late teens or twenties.
Investigators are asking anyone who was near Boyette's home the day of the murder to tell them what they know.
"Possibly when the crime first occurs, people may be a little less likely to call with information. As time goes on, they may feel a little more comfortable and give us a call," said Detective Amzie Hoffner of the Wilson County Sheriff's Office.
A reward of $100,000 is still being offered.