In 2010, Joseph McStay (age 40), and his wife Summer (age 43), lived in Fallbrook, California, with their sons Gianni (age 4) and Joseph Jr. (age 3). Joseph Sr. managed a company that built decorative fountains, and Summer was a licensed real estate agent.
On February 4, 2010, at 7:47 pm, a neighbor's surveillance system recorded a vehicle, later confirmed not to be the McStay family's vehicle due to muffler placement on the vehicle not matching that of the family's Isuzu Trooper. In the surveillance recording, the vehicle's occupants could not be seen. At about 8:28 pm, a call was placed from Joseph McStay's cell phone to his business associate, Chase Merritt. The call went to voice mail. Merritt later told police that he ignored it because he was watching a movie. Joseph's cellphone pinged a tower in Fallbrook.
Over the next several days, the McStays' family and friends unsuccessfully tried to contact them. On February 15, Joseph's brother, Mike, climbed into an open window at the McStay house. He did not find his brother or his brother's family, and their two dogs were in the backyard. Police were alerted prior to Mike entering the family's house, but did not act until afterwards. Although a search of the home found no evidence of struggle or foul play, there were indications of a hasty departure: a carton of raw eggs had been left on the counter and two child-size bowls of popcorn sat on a sofa.
During their investigation, the police learned that on February 8, the family's 1996 Isuzu Trooper was towed from a strip mall parking lot in San Ysidro, San Diego, near the Mexican border. It was believed that the vehicle had been parked there between 5:30 and 7 pm that evening. At 11 pm, security guards towed the vehicle. The car's location from February 4 to February 8 is unknown.
The circumstances surrounding the family's disappearance and the lack of clues about their whereabouts triggered speculation by amateur sleuths. Radio host Rick Baker published a book, No Goodbyes: The Mysterious Disappearance of the McStay Family. Baker began following the case in 2011, after interviewing Joseph's brother, Michael, on his program. Baker conducted dozens of interviews on the case (traveling to Belize, Mexico, Haiti and the Dominican Republic), followed leads and reported sightings of the family. Baker, critical of Summer McStay in his book, speculated that she might have committed the murders. Michael McStay criticized Baker and the book's accuracy, saying, "I don't know how he sleeps at night. I suspect he's looking for money. He's a good manipulator and knows how to twist things. He's just trying to sell books."
When the bodies were found, Baker offered a refund to those who purchased his book before November 2013. He said that he did not believe that drug cartels were responsible for the deaths, citing the placement of the McStays' vehicle after their disappearance: "Why would they stage their car at the border, cartels don’t do that." Although involvement by the McStays with Mexican drug cartels was one of many theories suggested after their disappearance, no supporting evidence has been found.
After their disappearance, it was speculated that the McStays left voluntarily, since investigators found searches on the family's computers for "What documents do children need for traveling to Mexico?" and Spanish language lessons. Because their car was found so close to the Mexican border, police reviewed surveillance footage of the pedestrian gate into Mexico. Video recorded the evening of February 8, released on March 5, showed a family of four resembling the McStays crossing the border into Mexico. On February 19, 2010, California police notified Interpol to be on the lookout for the family. In April 2013, the San Diego County Sheriff's Department announced that it believed that the McStays traveled to Mexico voluntarily. Several unconfirmed sightings of the family were reported in Mexico and elsewhere, perpetuating hopes that they were safe and had left voluntarily. Relatives of the McStays doubted that they would travel to Mexico, saying that Joseph and Summer avoided the country because of the safety threat posed by recent drug wars. Other critics of the theory noted that the McStays had over $100,000 in bank accounts, with no withdrawal of funds in preparation for a trip, and their accounts were untouched after their disappearance. Summer's sister said that Summer's passport was expired. Although it is possible for a US citizen to enter Mexico without a passport, one is required to reenter the United States.
The mystery deepened when rumors spread that, despite substantial bank holdings, the McStays experienced financial difficulties in the months before their disappearance. A former neighbor told The Daily Mail that the family was on the verge of eviction just before purchasing their $230,000 home in Fallbrook. Investigators and family members deny finding any evidence of financial problems.
Summer had been known by a number of names. Born "Virginia Lisa Aranda", she had also been known as "Summer Martelli", "Summer Aranda-Martelli", "Lisa Aranda", "Lisa Martelli" and "Lisa Aranda-Martelli". In an early video interview Summer's mother confirmed that Martelli was the surname of Summer's stepfather, but it was later alleged to have been invented by Summer. In a February 25, 2010 Valley News article, Sheriff's Lt. Dennis Brugos "confirmed that Summer McStay was previously known as Lisa Aranda and/or Lisa Martelli. He was uncertain when she changed her first name to 'Summer', or if it was done legally. Brugos said her legal maiden name was Aranda, but at times she used her stepfather’s last name of Martelli, although she was never adopted by him." She took 10 years off her age, although there was no confirmation that she used the alternative birthdate on a legal document. Family members insisted that the name change was only a facet of Summer's eccentric personality.
Investigators and the public also focused on McStay's business partner, Chase Merritt, who was the last known person to have had contact with Joseph McStay, and was the first to notice his disappearance. According to state records, Merritt had felony convictions for burglary and receiving stolen property. His most recent felony conviction, in 2001, was for the theft of $32,000 worth of welding and drilling equipment from the San Gabriel Valley Ornamental Iron Works in Monrovia, California. An acquaintance of Merritt's told a San Diego reporter, "I think police should look at him and anyone associated with him."
In 2013, Merritt acknowledged he spent more than an hour with Joseph McStay the day he and his family went missing from their home in suburban San Diego County. Merritt, who claimed to be the last person McStay called from his cellphone, also said that he had passed a polygraph exam and did not know anything that could help solve the family's disappearance. When asked if he thought Merritt was a suspect, Joseph McStay's father Patrick said, "I have to have faith in Chase because I have to have faith in my son. I believe that (Joseph McStay) trusted Chase and believed in Chase. Do I think Chase is involved? I don't think so and I truly hope not."
In January 2014, Merritt said that he might write a book about the family, alleging that Summer had anger issues and that Joseph had been ill for some time with a mysterious ailment. Although Merritt feared that Summer was poisoning him, he did not believe she was responsible for the deaths. Joseph McStay's family confirmed that Joseph had an unexplained illness and that Summer was possessive of her husband, but they called the accusations unfounded. Joseph's father Patrick said, "I truly believe she loved my son."
In 2013, local news reported that the McStay family had called Summer's ex-boyfriend, Vick W. Johansen, a person of interest in the case; the family believes that email records demonstrate that Johansen was obsessed with Summer for years after their relationship ended. The McStays noted his criminal history (violent threats, felony vandalism, disturbing the peace, interfering with a business and resisting a peace officer) and a pattern of movement around the time of the disappearance that they considered suspicious. The San Diego Police Department had no comment on Johansen, defending its work in the case.
On November 11, 2013, a motorcyclist found four sets of human remains buried in two shallow graves in the desert near Victorville, California. Patrick McStay was informed of the discovery and phoned missing person advocate Jerrie Dean of Missing Persons of America to tell her of what he knew. Jerrie Dean stated in her blog she had just finished producing a radio show for KNSJ when Patrick phoned her that evening. She stated on her blog she asked him if she could tell her followers of what he had told her, and was unprepared for the media storm that hit the following morning. Two days later, these remains were officially, positively identified as those of Joseph and Summer McStay. The deaths were ruled a homicide and authorities of San Bernardino County said that they believed the family died of blunt force trauma inside their home, but declined to discuss specifics of the deaths or a motive.
Days after the discovery of the bodies, Joseph McStay's father said that the San Diego police investigation was faulty. He filed formal complaints in 2013.
On November 5, 2014, California authorities arrested McStay's business associate Chase Merritt in connection with the deaths of the McStay family after discovering that his DNA had been recovered from the McStays' car. His arrest was announced on November 7, 2014. Merritt is awaiting trial for four counts of murder, and the district attorney is seeking the death penalty. In July 2015, Merritt's defense attorney filed a request to have the case dismissed because of the wording used by the prosecution when the charges were filed.
According to arrest warrant affidavits filed in the case, autopsies concluded that all four victims had been beaten to death with a blunt object, and investigators believe the murder weapon was a 3-pound sledgehammer, which was found in the grave where Summer McStay and one of her sons were buried. Investigators testified that they believe the victims were tortured before they were killed.
Prosecutors allege that Merritt had a gambling problem and killed the family for financial gain. They said that he wrote checks totalling more than $21,000 on Joseph McStay's business account in the days after they were killed. He then went on a gambling spree at nearby casinos, where he lost thousands of dollars.
Trial has been delayed as Merritt has repeatedly fired his attorney or attempted to represent himself. As of February 2016, he had gone through five attorneys.
As of November 2016, Merritt was still awaiting trial.