James Ricks (holding guitar) in an undated family photo. Ricks was murdered in 1967, and his killer, James Leon Clay, was brought to justice nearly 50 years later. (Photo: Courtesy of Julius Ricks via the FBI)

Two brothers were arrested in the summer of 1967 and convicted of robbing a pawn shop, stealing a car and possessing concealed handguns illegally. But they were not charged with the killing of the owner of the car, whose body was found decomposed in the woods two months after they were caught.

But the execution-style killing of James Ricks caught up to James Leon Clay, now 70, in the most mundane of ways.

He couldn’t stop talking about it.

Clay had told his cellmate in a Delaware prison of the slaying 45 years earlier in 2012, according to a new account provided by the FBI. That jailhouse confession would kick off a new investigation—and a new conviction for the killer.

The tip came into the FBI from the brother-in-law of the cellmate at the Sussex County Correctional Facility in Delaware in 2012.

Special Agent Justin Downen of the Baltimore field office’s Dover Resident Agency and Officer Derrick Calloway of the Laurel Police Department in Delaware interviewed the cellmate of Clay. Downen had fielded the tip, and Calloway was the cop who had investigated the unrelated bank robbery that had put Clay in prison at the time, according to the FBI account.

They said Clay had bragged about killing a man back in Arkansas decades before. The cellmate gave details of the Arkansas killing which only the perpetrator would know.

The cellmate even apparently took notes on the lengthy discussions from the top bunk of the cell while Clay talked on the bottom bed.

James Leon Clay (Photo: Courtesy of the Delaware Department of Corrections)

The story checked out, from the court documents and those who were around to recall details of the murder.

“Then it was just a matter of how we would prove it,” said Downen. “The case is 50 years old, so the only way we get a conviction is to get the guy on tape admitting to it.”

But the two investigators had to wait. The cellmate had already been moved to another prison, and they had to be able to get a taped confession, somehow. As the two years wound by, Calloway was transferred to another police department, and Downen would check on Clay’s incarceration status intermittently.

Clay was released in August 2014. They had to set up an orchestrated meeting between the old cellmates. The probation office was selected as the most probable site of an encounter.

The cellmate, wearing a wire, had a “chance meeting” with his old friend Clay on Dec. 18, 2014. They caught up with what had happened in the last few years and since their release—and then the cellmate coaxed the story of the murder out of Clay, first in the probation office, and then also in Clay’s truck outside.

The tale went thus: the Clay brothers’ getaway car broke down after they robbed the pawn shop in North Little Rock. They rushed up to the 1964 Oldsmobile where Ricks, then 27 and a father of a young girl, was sleeping.

One of the Clay brothers shot Ricks, and they handcuffed him in the trunk of his car.

They drove about 90 miles to rural Arkansas.

It was at a farm near the town of Newport that James Leon Clay, then 20, shot Ricks in the back of the head. The brothers then dumped the body in a wooded area.

Clay said it was his brother who had told him to do it—and that he regretted the killing. But investigators were unsure how much of that was bragging and how much of it was an attempt to appear tough behind bars.

Clay and his brother Leon Junior Clay, then 25, were arrested in Ellicott City, Maryland, on June 20, 1967 on robbery, car theft and weapons charges.

But even though they were caught with Ricks’ car, the two brothers were never charged with his murder. The decomposed remains of Ricks were found on the farm accidentally by two hikers on Aug. 27, 1967.

Clay told his cellmate of encountering the Ricks family at his trial for the car theft.

The elder Clay brother died in the ensuing years.

The younger Clay brother compiled a criminal history that included shoplifting, criminal trespass and other charges in addition to the masked bank robbery in 2011. He has been diagnosed with chronic paranoid schizophrenia. For the Ricks killing, he was finally arrested and charged with first-degree murder on May 10, 2015 at his ramshackle house, which was condemned the same day.

Clay fought extradition—but eventually pleaded guilty in November 2016 to second-degree murder charges, and was sentenced to 20 years behind bars.

“It’s really easy to put yourself in the shoes of that family and think about what it would be like to lose a loved one under those circumstances and not have justice," said Downen.

The Associated Press contributed to this report