McRAE, Ga. (AP) — A man answering a Craigslist ad from a couple who wanted to buy a 1966 Mustang robbed, shot and killed the husband and wife when they traveled several hours to buy the classic car, a sheriff said Tuesday.

The bodies of 69-year-old Elrey "Bud" Runion and his 66-year-old wife, June Runion of Marietta, Georgia, were found Monday not far from where their SUV was discovered in a lake near McRae, Georgia, a small farming community of 5,700. Authorities had sent the bodies to a crime lab to confirm their identities. They had been shot to death, said Telfair County Sheriff Sheriff Chris Steverson.

The Runions' had been reported missing on Thursday by their daughters after they failed to show up to babysit their grandchildren.

Ronnie Adrian "Jay" Towns, 28, of McRae, the suspect who was already in custody on charges of attempting to rob the couple, has been charged with malice murder and armed robbery, Steverson said.

Steverson said robbery does appear to be the motive for the couple's killings, but he would not say whether the Runions were carrying cash or disclose other details about the case. On Monday, he said investigators had found no evidence that Towns owned the sort of classic car Runion was seeking.

Residents of McRae, a tiny city about 80 miles southeast of Macon, were stunned, trying to understand what happened to a young man who was known as a "very smart" and "good kid."

"This community feels betrayed," Steverson said. "For an individual who was raised in this community to have orchestrated such a heinous act, we are very upset to say the least."

Before Towns had been charged with their deaths, the sheriff had said a cellphone used to make the last known contact with the Runions had been traced to Towns, who turned himself in Monday accompanied by family members.

As of Tuesday, he remained the only suspect, said Jimmy Johnson, chief deputy at the sheriff's office.

The arrest also shocked Towns' family. He grew up on a farm beside a long dirt road where his father grew soybeans, cotton and peanuts. The property isn't far from where the bodies were found.

Towns lived in neighboring Wheeler County with his family — a wife and a young daughter whom he supported by doing construction work for a local homebuilder, said his uncle, Buddy Towns.

"He's a good kid, and very smart," said the uncle, who often saw his nephew's truck pass his McRae business as Jay Towns headed to work. "It just doesn't make any sense why this would even go down. It's hard for his parents. They're not understanding."

Much remained unknown about what happened to the Runions from the time the couple left home Thursday until authorities found their SUV Monday. The sheriff has said he planned to keep some details of the case under wraps until it goes to court.

"Our hearts really go out to the Runion family," Buddy Towns said. "We'd just like to let them know there are not all bad people in the world."