Huanting Gong, 30, of Glendale, is accused of then stealing $250,000 in luxury goods from the couple's home after disposing of their bodies.
Gong has been charged with multiple felony counts of murder, kidnapping, arson and burglary, and faces the possibility of life in prison without parole, or potentially the death penalty, if convicted.
Investigators believe Gong owed $80,000 to a business associate, 37-year-old Kuanlun Wang of Brea.
Instead of paying up, he allegedly met Wang in the desert on Oct. 12, shot him in the head and put his body in the victim's own Tesla, according to Orange County prosecutors.
He drove the Tesla back to Wang's home in Brea and then allegedly attacked the victim's wife, 37-year-old Jing Li, with a hammer to force her to give up her phone's password, the District Attorney's office alleges.
He is then accused of driving her to the desert in San Bernardino, shooting her and burning her body. He allegedly drove back to Brea to pick up Wang's body, setting the body on fire and disposing of him in a desert in Riverside County.
He allegedly brought the couple's two Teslas to two different desert areas and also set them on fire.
He allegedly returned to the Brea home on Oct. 14 and stole nearly $250,000 in watches, shoes, handbags and clothing.
"Depravity does not adequately describe the callousness involved to kill a human being and then drive around in the victim's own car with his body inside in order to carry out the rest of his plan," said Orange County District Attorney Todd Spitzer. "No one deserves the fate of being executed and then set on fire in the middle of the desert in a desperate attempt by a killer to cover up his crimes. We are committed to pursuing justice for the victims and their loved ones."
Brea police started looking into the case on Oct. 15, when a family member reported not hearing from Wang for several days. That family member had reportedly reached out to Gong on Oct. 12 - the same day as the murder - who claimed the couple never showed up for a planned trip to New York City where they were supposed to receive the $80,000 that Gong owed Wang.
After further investigation, Gong was arrested on Nov. 5 at Los Angeles International Airport when he returned from a trip to Seattle.
Gong is set to be arraigned in Santa Ana on Dec. 2