The family of four appeared to have left their Fallbrook home in a hurry, vanishing into the chill of a February night. A carton of spoiled eggs and a rotten banana sat on their kitchen counter. Neighbors began to feed the family's dogs.
Their SUV turned up four days later parked at a strip mall near the border with Mexico, a country that friends said the McStays would never think of visiting.
For nearly four years, it was a mystery that confounded investigators.
But on Friday — a year after the family's skeletal remains were found in shallow graves near Victorville — authorities finally declared that the vexing case had been solved.
Charles "Chase" Merritt, 57, was arrested on suspicion of killing former business associate Joseph McStay, along with his wife and two young sons, San Bernardino County Dist. Atty. Mike Ramos said.
All four died from blunt force trauma.
"I don't need to tell you this is a cold and callous murder," Ramos said. He said he may seek the death penalty if Merritt is convicted.
Since Joseph, 40, and Summer McStay, 43, disappeared Feb. 4, 2010, along with their sons Gianni, 4, and Joseph Jr., 3, authorities fielded hundreds of tips from callers with purported sightings phoned in across the country.
Someone thought they spotted Summer at an Ikea in Burbank. Another placed the family at a restaurant in Baja. A detective investigated a sighting in Indiana.
A check of the family's computers showed a search on necessary documents for traveling with children to Mexico as well as a possible interest in learning Spanish. However, those close to the McStays insisted that the couple were wary of the drug wars in Mexico and that Summer McStay was excited about remodeling the house and planting a garden.
Authorities compiled thick binders of evidence, but had no real leads.
The intrigue attracted national media, while the lack of answers frustrated family members. Joseph McStay's father, Patrick, long complained about the "lousy" and "inept" work of San Diego County sheriff's investigators.
Eventually handed off to the FBI, the case took a dramatic turn when an off-road motorcyclist discovered bones in a desert patch near Interstate 15 in San Bernardino County last November. Dental records confirmed that they belonged to the McStays.
A week later, Merritt was quoted in a British tabloid as saying that he had been the last person Joseph McStay phoned before he disappeared and that the two, who worked together in the water fountain business, had spent more than an hour together that day.
According to the Daily Mail article, Merritt said that sales had been flourishing at the time and that they had landed a lucrative foreign contract: "I was manufacturing all the waterfalls he was selling and I lost my entire business. Without his sales, I had nothing. I went bankrupt very soon after he disappeared."
Merritt added that he had taken a polygraph test and wanted to do anything he could to help find the killers.
"He was my best friend and we told each other everything," he said.
The Riverside County resident has a long history of petty crime, violating court orders and drifting between blue-collar jobs.
In 2001, he pleaded no contest to second-degree burglary and grand theft after he was accused of stealing from a San Gabriel Valley ironworks company. He was sentenced to 180 days in county jail and ordered to serve three years' probation, but it took him nearly 10 years to complete his probation after he routinely failed to attend court-ordered programs or pay fines. He eventually completed his probation seven months after the time when prosecutors say the McStays were murdered.
At the time of the McStays' disappearance, detectives believed that the family left on their own accord and planned to return. There were no signs of struggle or forced entry. A neighbor's surveillance camera showed the McStays' Isuzu Trooper driving away about 7:45 p.m.
But authorities now say the McStays were killed at their home, on a cul-de-sac beneath a hillside lush with avocado trees.
San Bernardino County Sheriff's Cpl. Randy Naquin said investigators combed through 4,500 pages of material, served 60 search warrants and conducted more than 200 interviews. Evidence from the McStays' grave site led them to Merritt, Sgt. Chris Fisher said.
Escorted into a packed Victorville courtroom Friday, Merritt wore a green jumpsuit and kept his eyes away from the throng of reporters and the benches filled with relatives of the McStays. His own supporters stood nearby, clinging to one another while sobbing. His arraignment was postponed until next week.
Merritt's brother, Bennett, said the allegations were false. "My brother's not guilty and we don't want to talk to you reporters anymore, period," he told The Times.
But Susan Blake said she had long suspected that Merritt killed her son and his family, calling it "mother's intuition." She said that her son had often given money to Merritt.
Michael McStay said his brother, who owned Earth Inspired Products, had given Merritt work to help him. "And this is how he was repaid?" he asked.
Still, the arrest offered the family a chance at laying some of their questions to rest.
"I know it's trite, but this gives our family a little more closure, an opportunity to heal and move forward," Michael McStay said.
For years, he operated a website that posted updates on the case and encouraged readers to share tips on the family's whereabouts. "Let's bring them home safe!!!!!" it read when it first went up in 2010.
The last post was in July, a week after the funeral of all four McStays.
"One of the hardest [things] I've ever had to do was to watch my mom see her son, daughter-in-law, and grandsons' ashes be lowered into the small shallow plot," he wrote.