Authorities on Friday announced they had arrested Joseph McStay's business partner on suspicion of murder in the deaths of McStay, his wife and their two young children. The family's remains were found in shallows graves last year on the edge of the desert in Victorville.
At a news conference held by the San Bernardino County district attorney and the Sheriff's Department, authorities said Charles "Chase" Merritt, 57, had been arrested on suspicion of killing Joseph and Summer McStay and their two young boys in 2010.
The cause of death was determined to be blunt force trauma. Investigators said they believed the killings took place at the family's home in Fallbrook, Calif., but did not release a motive.
Merritt was arrested Wednesday. His arraignment in San Bernardino County Superior Court on four counts of murder was postponed until Nov. 12.
Merritt will be eligible for the death penalty if convicted, Dist. Atty. Mike Ramos said.
"I don't need to tell you this is a cold and callous murder on an entire family," Ramos said.
Merritt's arrest comes nearly a year after he gave an interview to the British tabloid Daily Mail in which he said he spent more than an hour with Joseph McStay the day he and his family went missing from their suburban San Diego County home.
Merritt, who said he was the last person Joseph McStay called from his cellphone before disappearing, claimed he did not know anything that could help solve the crime.
He said he was questioned by police and submitted to a polygraph examination.
"It is not about finding them," he told the newspaper, "it's about finding the people who did this, and if anything I say can help jog someone's memory or offer some clue, then I'll be happy."
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 as they followed up on 250 tips in the case.
Reached by phone after the charges were announced Friday, 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 said.
Charles Merritt and Joseph McStay ran a fountain-making business that by all accounts was doing well.
"There's no reason, no motive … for that ever to occur," Ramos said Friday of the slaying of the family of four.
Joseph McStay's brother, Michael, told reporters the arrest was a positive development.
"I know it's trite, but this gives our family a little more closure, an opportunity to heal and move forward," he said.
He added that all his brother had done was try to help Merritt "and this is how he was repaid."
"He'll get what he's got coming to him," Michael McStay said.
The McStays disappeared without a trace in February 2010, their car found abandoned in the parking lot of a mini-mall near the Mexican border.
In November 2013, investigators identified remains found in two desert graves as those of Joseph Stay, 40, and Summer McStay, 43, and their boys, Joseph Jr., 3, and Gianni, 4.
The remains were found by a motorcyclist in a remote area off the 15 Freeway outside Victorville.
It was a tragic end to what had been long-running missing persons case that befuddled investigators and family.
After concerned relatives reported the family missing, investigators found no sign of a struggle in the McStay's Fallbrook home.
Neighbors said they hadn't seen them for days and started feeding the family's dogs.
Investigators said at the time that the family's life appeared normal and then one day they simply vanished.
The case was initially handled by San Diego County sheriff's officials, but the investigation is now being led by the San Bernardino County Sheriff's Department.