Only Channel 2 Action News was with investigators as they returned to one of the scenes in an elderly couple's killing in Putnam County Wednesday afternoon.

Channel 2’s investigative reporter Mark Winne was the only reporter on the sheriff's boat behind the home on Lake Oconee just hours after investigators finished another search at the home.

Deputies say someone killed and beheaded 88-year-old Russell Dermond on May 2 at his home in Great Waters Reynolds Plantation.Fishermen discovered the body of 87-year-old Shirley Dermond two weeks later in Lake Oconee.

Putnam County Sheriff Howard Sills told Winne that he has evidence indicating the killer used two different weapons during last month's slayings. Sills says physical evidence points to a strong likelihood that the Dermonds died in different ways and that the killer, or killers, used a different kind of weapon to kill 88-year-old Russell Dermond than to kill 87-year-old Shirley Dermond.

“I don’t believe they were killed with the same weapon, no,” said Sills. “I won’t elaborate on what the murder weapons were.”

Tuesday, the sheriff announced a $30,000 reward for information leading to the arrest and conviction in this case. He also said he expects that reward to grow rapidly, as he asked the community for donations.

It was the first time in his four decades in law enforcement that Sills says he has offered this kind of reward. Sills said Tuesday the phone calls had dried up and they need the public’s help to find new information and leads. However, Sills says he, his investigators and the FBI have not come away from the Dermond’s home empty-handed.

“This is a very difficult case, but that doesn’t mean we don’t have forensic evidence. We’re running down leads today,” said Sills. “We’ve got fingerprints, we’ve got hairs, we’ve got fibers, we’ve got all matter of forensic evidence that we’ve collected from the house.”

Sills said they’ve also collected several other items of significance to the case that he can’t talk about.

"What's in my heart is finding out who killed these people,” said Sills.

Sills says he believes whoever killed the Dermonds left Russell Dermond’s headless body where it would be found, but never planned for Shirley Dermond’s remains to float to the surface of the lake and be discovered.

“I think it was a matter just to distract us, to concentrate our attention towards the whereabouts of Mrs. Dermond; whether we suspected her to be a suspect or we suspected that she had been abducted,” said Sills.

The Putnam County Sheriff's Office has set up a hotline for tips in the case. If you have information that could help investigators, call 706-485-8557.