When his father-in-law died en route to a vacation in Florida, Ricky James Bennefield stopped the car and gave his family an order: Bury him.

The body now resting in a shallow grave alongside the road, the family continued on their way toward Florida. But Bennefield, who already was carrying a dark secret, was worried – was the grave deep enough to avoid discovery?

So, court records reveal, Bennefield drove back to the makeshift grave site, ordered his wife and at least one child to help dig up his father-in-law’s body and put it back in the car. Bennefield then drove to a site he found more suitable for a secret grave and again enlisted the family's help in burying the body.

“The family continued on their vacation destination, telling no one of (Franklin D.) Chastain’s death,” Assistant U.S. Attorney Jennifer Kolman wrote in a document filed in U.S. District Court.

No body, no crime?

Even now – eight years after Chastain’s death – authorities have no idea where his body is or how he died. Bennefield, who admits the series of events in June 2010 detailed by Kolman, insists Chastain died from natural causes but that he cannot remember even in what state Chastain is buried.

Bennefield, 53, pleaded guilty this week before Senior U.S. District Judge Thomas Phillips to charges of conspiracy to commit mail and wire fraud, theft of government money and aggravated identity theft for continuing to collect Chastain’s social security and pension benefits to the tune of more than $121,000 in six years.

He is already serving a prison term for that other secret he had been carrying – molesting the child he twice forced to help bury Chastain. In a plea deal with 4th Judicial District Attorney General Jimmy Dunn’s office, Bennefield received a five-year sentence in December after pleading guilty to rape and a related charge for molesting the girl in 2008 in separate instances in Cocke and Sevier Counties, court records show.

Erika Nicole Bennefield – Ricky Bennefield’s 46-year-old wife and Chastain’s daughter – has pleaded innocent in the conspiracy to trick the Social Security Administration into believing Chastain was alive and cashing his own benefits and pension checks. She was not charged in the rape case against her husband.

USA TODAY NETWORK-Tennessee is not identifying the rape victim’s relationship to the Bennefields in keeping with the news organization’s policy of protecting from disclosure the identity of victims in sexually-based crimes.

It was the rape victim who first told authorities about Chastain’s death, according to the factual basis Kolman filed in Bennefield’s federal case.

A victim's surprising story

Authorities in Cocke and Sevier Counties began investigating the rape allegations in late 2016. The Bennefields had lived in both locales – as well as in Georgia and Alabama – in the past decade.

In a December 2016 interview, the rape victim surprised authorities with the tale of the June 2010 family vacation and Chastain’s death, Kolman wrote. Chastain lived in Alabama at the time. The rape victim told authorities Chastain died in the car. She did not know what caused his death but told authorities Bennefield feared law enforcement involvement.

“The defendant buried his father-in-law to avoid Chastain’s death looking like foul play because Chastain’s body was covered in bruises,” Kolman wrote.

After the rape victim disclosed the circumstances of Chastain’s burial, local authorities contacted a Social Security Administration agent. That agent, Kolman wrote, confirmed both Ricky Bennefield and his wife continued to collect and cash Chastain’s social security and pension benefits checks after his death.

Kolman, court records indicate, is gearing up for a fight for tougher-than-usual sentencing for Bennefield in the conspiracy case.

No plea deal has been brokered, and Phillips has set a special hearing July 9 to determine Bennefield’s penalty range given the unusual nature of the underlying facts.