[2] On November 7, 2014, police announced they had arrested Charles "Chase" Merritt, Joseph McStay's business partner, and intended to charge him with the murders.

[6] Joseph owned and operated Earth Inspired Products, a company that built decorative fountains, and Summer was a licensed real estate agent.

[8] On February 4, 2010, at 7:47 pm, a neighbor's surveillance system captured the bottom eighteen inches of a vehicle, thought at the time to be the McStay family's 1996 Isuzu Trooper.

On February 13, Joseph's brother Michael traveled to the McStay residence where he climbed through an open window in the back and gained entry to the home.

Although a search of the house found no evidence of a struggle or foul play, there were indications of a hasty departure: a carton of eggs had been left on the counter, and two child-size bowls of popcorn sat on a sofa.

Patrick McStay, Joseph's father, was informed of the discovery and phoned missing person advocate Jerrie Dean to tell her what he knew.

[13] Dean stated in her blog she had just finished producing a radio show for San Diego station KNSJ when she received the call, and that she asked whether she could tell her followers what he had told her.

He conducted dozens of interviews on the case (traveling to Mexico, Belize, Haiti, and the Dominican Republic), followed leads, and reported sightings of the family.

[16] 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?"

[19] 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.

His most recent felony conviction, in 2001, was for the theft of $32,000 worth of welding and drilling equipment from San Gabriel Valley Ornamental Iron Works in Monrovia, California.

[23] Merritt, who reportedly was the last person Joseph called from his cell phone, also said that he had passed a polygraph test and did not know anything that could help solve the mystery of the family's disappearance.

"[22] 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.

"[25] On November 5, 2014, detectives from the San Bernardino County Sheriff's Department arrested Merritt in connection with the deaths of the McStay family after discovering that his DNA had been recovered from their car.

They said that he wrote checks totaling more than $21,000 on Joseph's business account in the days after the family was killed and then went on a gambling spree at nearby casinos, where he lost thousands of dollars.

[29] Merritt's attorney filed a motion in San Bernardino Superior Court on April 7, 2018, arguing that Joseph's business and accounting records were hearsay evidence and therefore inadmissible.