New DNA evidence discovered in unsolved Lake Oconee killings

Catch up quick: Ten years ago this month, a friend discovered the headless body of Russell in the garage of the couple's $1 million lakefront home. Ten days later, a fisherman discovered Shirley's body in the lake.

• Investigators ruled out robbery or burglary, and the lack of motive in the case has puzzled family members, law enforcement and true crime aficionados.

The latest: Newly discovered DNA on evidence found near Russell's body does not belong to him, Putnam County Sheriff Howard Sills, a cigar-chomping character straight out of central casting, told WSB in late April. A Texas lab is now analyzing the material.

• FBI Special Agent Andy Smith told the outlet that investigators are using advances in analyzing cellular data linked to devices that might have been used near the crime scene.

Yes, but: Sills could not confirm whether investigators have enough DNA material to run through a national database or genealogical search — or whether it belongs to a potential suspect.

State of play: The FBI is offering a $20,000 reward to anyone who provides information leading to the arrest and conviction of the killer or killers.

Read AJC's coverage on the new evidence, Sheriff Sills and the Dermond family