(CNN) -- The Georgia couple is described as "sweet as can be," and authorities are scrambling to unravel the mystery of how Russell Dermond, 88, was killed and then reportedly decapitated, and his 87-year-old wife disappeared.
The Putnam County Sheriff's Office is treating Shirley Dermond's disappearance from the Eatonton home -- where her husband was found dead Tuesday -- as an abduction, Sheriff Howard Sills said in a statement.
Police suspect that Russell Dermond was killed between Friday and Sunday.
The Dermonds' friends hadn't heard from them in days and went to their home in the upscale, gated, lakeside Great Waters community, where they found in the garage "what we are virtually certain is the body of 88-year-old Russell Dermond," Sills said.
He would not elaborate on why police couldn't identify the body, but CNN affiliates WSB and WMAZ report that Russell Dermond was decapitated. WSB cited a law enforcement source in reporting that the head was not at the crime scene.
Pressed Thursday on that report, Sills said information suggesting that authorities had found parts of Shirley Dermond's body were "totally false" and asked CNN to "help stop the false reports, as they are interfering with our investigation."
However, he would not debunk the report that Russell Dermond was beheaded.
"I am only confirming at this time that Russell Dermond's body suffered significant trauma. An autopsy will be performed at the state crime lab today, and I may say more about that upon its completion," he said.
A Georgia Bureau of Investigation source confirmed the bureau was conducting an autopsy but wouldn't comment further.
Putnam County Deputy Coroner Mark Turner said "there were some conditions outside of the ordinary, to say the least" but wouldn't elaborate.
"Due to the state of the body we were not able to make a positive ID," he said. "However, the body did match the basic physical description of Mr. Dermond."
The FBI is also assisting and, likewise, reticent, saying only that it "is providing limited support based on the needs and requests from Putman County authorities," said Stephen Emmett, spokesman for the FBI's Atlanta office.
Police are asking for assistance in finding Shirley Dermond, who is 5-foot-2 and weighs 148 pounds. She has gray hair and blue eyes. She is believed to be in danger, Sills told local media.
Anyone with more information should call the Putnam County Sheriff's Office at 706-485-8557.
Little else is known about the couple, both of whom were born in New Jersey, and police and friends are at a loss for why they would be the targets of such violence.
Compounding the mystery is that the home was pristine. There is no sign of a break-in, a scuffle or anything missing. Their vehicles were at the home, police said.
Their 3,300-square-foot Eatonton home is valued at more than $1 million and sits on Lake Oconee, about 75 miles east of Atlanta. Russell Dermond has paid taxes on a 23-foot fiberglass boat, and he reportedly owned several fast-food outlets. Tax records connect him to a Wendy's and a Chick-fil-A.
The Rev. David Key of Oconee Lake Community Church said he has known the couple for about eight years and counts them among his church's 350 attendees. He's "baffled" as to why anyone would commit such crimes against them, he said, as they were grounded, "beloved in the community" and "sweet as can be."
They were active in the church and family-oriented, he said. The Dermonds had three children, he said, as well as grandchildren, though he wasn't certain how many.
"Number one, we are devastated by Russell having died and the violence around that," Key said. "And not knowing what happened to (Shirley). ... It is dealing with the tragedy of what we do know and the uncertainty of what lies ahead."