He dressed up as Santa Claus. A fatal secret was buried in his backyard.

Investigators say Elwyn Crocker, 50, led police to the graves of his children Elwyn Jr and Mary after a tip-off compelled police to search his Georgia home. Photo / Effingham County Sheriff's Office

The neighbourhood kids noticed Mary Crocker's hands.

The rail-thin 14-year-old looked younger than she was, and reportedly always dressed in worn-out clothes. But it was her hands that drew attention. They were perpetually red and worked-over, the result of long hours the girl spent raking leaves and doing other lawn chores in the yard stretching out from her family's double-wide trailer in Guyton, Georgia, a rural town about 30 miles from Savannah.

"That was from being out in the yard out there most of the time working, doing stuff from the time she got off that bus until they would go in at night," the Crockers' neighbour, Gary Bennett, recently told Savannah's CBS television affiliate, WTOC. "Then she would go to school and kids would see her and ask what was wrong and she wouldn't ever say anything. She wouldn't open up to anybody."

But Mary's hours in the yard apparently ended last October - no one saw her again. Neighbours did, however, spot her father, Elwyn Crocker Sr., then 49, outside in the closing weeks of 2018. They would later tell WSAV, Savannah's NBC-CW+-affiliate, that he had a shovel near the tree line, near from the chain-link cage where the Crockers kept the pit bulls that caused problems with the neighbours.

The ugly reality about what was allegedly happening became clearer this week.

The holiday season was a busy time for Crocker. Bulky and wide, he climbed into a Santa Claus suit for customers at a local Walmart. His birthday is even on Christmas, when he turned 50 last month, the Atlanta Journal-Constitution reported December 26.

Elwyn Crocker Jr, 14, (left) vanished two years ago while his sister Mary, 13, was last seen in October. Their bodies were found buried in their father's backyard on December 20. Photo / Supplied

On December 20, five days before Christmas, local law enforcement received a tip that Mary was missing and might be dead. When Effingham County Sheriff's deputies searched the Crockers' property later that day, they discovered the girl's body buried near the tree line.

She was not alone. The search also turned up the remains of her brother, Elwyn "JR" Crocker Jr. The boy had not been seen since November 2016, when he was 14, authorities said in a news release.

Remarkably, no one had reported either child missing, Effingham County Sheriff Jimmy McDuffie told reporters at a December 20 news conference. The five adults living in the trailer were all arrested following the discovery: the father, Crocker; his wife and the children's stepmother, Candice Crocker; Candice's mother and brother, Kim Wright and Mark Wright; and Kim Wright's boyfriend, Roy Prater.

A third child, 11, was found unharmed at the house and taken into custody.

On Monday, all the suspects were served with felony murder warrants, WSAV reported. As the investigation continues, neighbours are struggling with guilt, wondering why they did not channel their suspicions and bad feelings about the family into actual complaints to authorities.

More alarming, however, are the red flags possibly missed by Georgia's child service agency.

"The biggest question some of us are asking is, how did the little boy go missing for two years and nobody identified that?" Effingham Sheriff's Office spokeswoman Gena Sullivan told the Journal-Constitution in December.

Crocker and his first wife had JR and Mary while living in South Carolina. After they split, Crocker had a third child with another woman, a boy with cerebral palsy, the Journal-Constitution reported. By 2010, he had relocated with all three children and his new wife, Candice, to Rincon, Georgia.

There, neighbours and friends noticed strange things about the family. Daniella Gills, 14, was friends with Mary at the time. The Journal-Constitution reported December 26 that Daniella said her friend never seemed at ease at home.

"She would never want me to leave her. If she went to the bathroom she would want me to go with her," she told the paper. "She wouldn't tell me why."

Stepmother Candice Crocker, 33, has been charged with concealing a death and child cruelty. Photo / Effingham County Sheriff's Office

Daniella said that if JR acted up, he was forced to sleep in the bathroom or closet as punishment, the Journal-Constitution reported. Gills' father, Marvin Gills, noticed flashing warning signs inside the Crocker household, including a lock on the refrigerator and constant complaints from Candice's family about the kids' behaviour. JR was a professional wrestling fan who loved to roughhouse; Mary did yard work in the neighbourhood to save up for a bike. The friend's father did not understand what the adults could take issue with.

"I feel bad because I missed something somewhere," Marvin Gills told the Journal-Constitution after the bodies were discovered. "It just eats at me."

When the family relocated to nearby Guyton, neighbours say the Crockers kept to themselves, the Savannah Morning News reported January 22.

Some neighbours had run-ins with the family over the pit bulls. The children's step-grandmother, Kim Wright, reportedly said she did not want JR and Mary associating with local kids. Both were enrolled in local schools before they were pulled out for home schooling.

Neighbours saw Mary working in the yard until dark, and spotted her father during the holiday season.

"This guy, the biological father, was a Santa Claus at Rincon Walmart, and these other families who live out here had their kids in his lap," neighbour Ronald Howe told Savannah's CBS affiliate, WTOC.

State investigators, however, had the Crockers on their radar.

Georgia's Division of Family and Children Services investigated allegations that JR was being abused in 2012 and 2013, the Journal-Constitution reported January 19. Parenting classes and counselling were recommended. Then, in March 2017, a girl told a school counsellor about an incident she had allegedly witnessed a year earlier: A family member had beaten JR with a belt for more than an hour.

The state agency declined to investigate because the incident was not recent.

"The report was about something that happened in the past," Walter Jones, director of communications and legislative affairs for the Georgia Division of Children and Family Services, told the Savannah Morning News. "We had no information any of that was ongoing."

Authorities now believe JR may have already been dead by the time the complaint was made.

Since the bodies were discovered, the state has instructed its child service agency to take complaints about past abuse more seriously, the Journal-Constitution reported January 28.

"Those who knew the children have expressed a sense of responsibility and regret for not coming forward with their concerns sooner," the agency head said in a statement. "They are not - and should not be - the only ones. We have a shared responsibility."

Authorities have not released a cause of death for either JR or Mary. The five family members charged in the case have not yet been arraigned on the murder charges.