Charles “Chase” Merritt, a business partner and friend of Joseph McStay, has been arrested for murdering Joseph, his wife and his two young children.

Man Arrested For McStay Murders

Merritt, 57, was arrested Wednesday in Chatsworth, Calif., Detective Chris Fisher told CNN. He has been charged with four counts of murder for the deaths of married couple Joseph and Summer McStay and their two sons – Gianni, 4, and Joseph Jr., 3. A motive for the murder has not been revealed.

San Bernadino County District Attorney Michael Ramos has yet to announce whether or not he’ll seek the death penalty for Merritt, calling Merritt’s act a "cold and callous murder of an entire family."

The McStays went missing from their San Diego home in 2010. Their remains were discovered off Interstate 15 in San Bernadino County in two shallow graves and were identified via dental records. The cause of death was determined to be “blunt force trauma,” but no further details about the specifics of the murders have been revealed.

Merritt has long been a prime suspect in the murders, but has steadfastly maintained his innocence. "There are hundreds of scenarios," he previously told CNN, speaking about a phonecall from Joseph McStay on the night the family disappeared. "I have gone over all of them in my head. Of course I regret not picking up the phone."

Michael McStay, who has been outspoken during the investigation into the deaths of his brother, sister-in-law and nephews, is relieved that someone is finally being held accountable for their untimely ends. "You have no idea what this means," he said at a press conference. "I just wanted to see it through. Joseph was a great brother and a great father. He tried to help Chase and this is what he got.”