FLORENCE, KY (FOX19) - The Boone County Sheriff's Office and the children of Bill and Peggy Stephenson revealed new information Thursday in the couple's murder.
The Stephensons, both 74, were found dead in their Florence condo in May of 2011 after they didn't show up for church services.
Police have been able to retrieve the killer's DNA and enter it into the FBI's Combined DNA Index System, known as CODIS. So far, there hasn't been a match.
Sheriff's office spokesman Tom Scheben says it's a "matter of time" before the killer is caught. Scheben said investigators have questioned more than 250 people in 14 states throughout the case.
Investigators have also been able to determine that the Stephensons died between 1 and 4 a.m. on May 29, 2011 and that the killer spent a significant amount of time in the Stephensons' condo after the murders.
The Stephenson family has increased the amount of the reward for information from $5,000 to $100,000. A dedicated phone line has been put in place for tips. The number is 859-334-8496. A special page has also been set up on the Sheriff's Office website.
The Stephensons' nephew, Charles "Steve" Stephenson, is charged with murdering Leigh Jennings in Indiana. The DNA does not belong to him, but police have not ruled out the possibility that he could have been involved.