A New Book Reveals Details About What Happened to the McStay Family

A new book shares details about what happened to the McStays, a California family of four that disappeared from their Fallbrook home on February 4, 2010. Joseph McStay, his wife, Summer, and their two little boys, Gianni and Joseph Jr., vanished without a trace for several years.

Caitlin Rother is the author of the new book, Down to the Bone, and according to ABC10 News, she shares details about the investigation into the family's disappearance. Video footage was found of a family crossing the border into Mexico that led sheriff's deputies to conclude they'd left voluntarily, at first. So, what happened to the McStays?

Joseph McStay, his wife, Summer, and their two little boys vanished from their home in Fallbrook, Calif., back in 2010. They'd recently moved from Orange County, and their dogs were later found in the backyard. Eggs were also found left out on the counter inside the home, per NBC San Diego. Joseph's brother, Mike, asked the police to conduct a welfare check on Feb. 10, which they did, but they did not go inside.

On Feb. 13, Mike climbed into his brother's house through a window and found the eggs on the counter and the dogs in the yard. After a neighbor's video footage captured their Isuzu Trooper leaving the neighborhood, the authorities searched and later found that someone had searched the family's computer for information about passports traveling to Mexico with children.

In March 2013, the San Diego Sheriff’s Department announced that footage of the family indicated they'd entered Mexico voluntarily. Their vehicle was also found near the border. However, in November of that year, a motorcycle rider found human remains in the northern Victorville desert. Several days later, San Bernardino County Sheriff John McMahon revealed that the remains were Joseph, 43, Summer, 40, Joseph Jr., 3, and Gianni, 4. The family was identified through dental records and DNA.

According to Wikipedia, Joseph was the owner of Earth Inspired Products, a company that built water fountains, and he'd gone into business with a man named Charles "Chase" Merritt.

San Bernardino County District Attorney Mike Ramos said that the deaths were a "cold and callous murder of an entire family," per ABC7 News. A sledgehammer was found near their graves, and the manner of death was ruled as "blunt force trauma."

Merritt was arrested in 2014 and tried for the murders after his DNA was found in the family's vehicle. He was found guilty in 2019 and given a death sentence. He admitted to spending time with the family on the day they disappeared, and prosecutors claimed that he was addicted to gambling.

They alleged that he murdered the family for financial gain, and Merritt wrote more than $21,000 in checks on Joseph's business account days after the McStays were killed. He then went on a gambling spree at several casinos and lost thousands of dollars.

The author of Down to the Bone claims that there are unanswered questions about the investigation.

"There's just several unanswered questions and kind of bizarre mysteries and pieces of evidence that we can't account for," she said.

"They had no blood at the house tying Chase Merritt forensically to the house where he allegedly murdered them," she added. She also noted that another suspect in the case, Dan Kavanaugh, claimed to be in Hawaii with his girlfriend when the murders happened, but investigators never confirmed his alibi. Other DNA was also found on the vehicle, and Joseph's gun was found inside a felon's car, reportedly stolen from Las Vegas.

"They were never able to pin that down through a flight manifest that they were in Hawaii," she said of Kavanaugh. Kavanaugh denied he was involved in the killings, and Merritt is appealing his conviction.

A 20/20 special about the case will air on ABC on Oct. 3, 2025.