Dad Who Allegedly Killed Kids With Spear Gun Is Being Psychologically Evaluated In Jail

A California surf instructor who drove his two young children to Mexico and allegedly killed them with a speargun will undergo a psychological evaluation, officials said.

Matthew Taylor Coleman, 40, who is accused of murdering his 2-year-old son, Kaleo, and 10-month-old daughter, Roxy in Rosarito, Mexico, is currently being held in protective custody.

He’s now undergoing a court-ordered mental health analysis to determine if he’s competent to stand trial, according to PEOPLE.com.

Coleman, who claimed his wife had “serpent DNA and may have been passing it on to his children,” had become enamored with QAnon conspiracy theories, according to a criminal complaint obtained by Oxygen.com. 

"M. Coleman stated that he believed his children were going to grow into monsters so he had to kill them," the complaint stated.

On Aug. 7, Coleman’s wife contacted Santa Barbara Police to report her husband had fled in a Mercedes van with the couple’s children. She filed a missing person’s report the next day. She later used a computer-based app to determine Coleman had been in Rosarito, the complaint stated.

When Coleman attempted to cross back into the United States on Aug. 9, he was intercepted by border officials, who had been tipped off by the FBI and San Diego authorities. Customs agents first found bloody vehicle registration paperwork when searching the inside the van. When Coleman’s children weren’t found to be in the vehicle, agents contacted Mexican authorities, who advised two children’s corpses had been recovered near Rosarito. 

They’d suffered “large puncture wounds” to their chest.

Coleman was subsequently taken into custody. Under questioning, Coleman confessed to the pair of killings, according to the criminal complaint.  

He allegedly told detectives he pulled over to the side of a road around 5 a.m. on Aug. 7 and used the spear gun to shoot his 2-year-old son and 10-month-old daughter in the heart. He later abandoned their bodies in the desert, according to authorities. Coleman allegedly then tossed the spear gun and bloody clothes near a creek and disposed of more bloody garments in a garbage bin at a roadside near Tijuana, Mexico.

Mexican authorities later seized the spear gun suspected to have been used in the double slaying, as well as the bloody clothes. A "blood-stained wooden stake” was also retrieved from the scene of the murder, according to The San Francisco Gate.

The gruesome slaying has rocked Coleman's family, particularly his wife.

"Abby is devastated," a family friend also told PEOPLE.com. "She is confused, stunned and just destroyed inside. She never had any idea he thought all these things. She thinks he just snapped. Something must have happened in his brain."

Coleman previously waived his right to a preliminary hearing. He hasn’t yet entered a plea.

His public defender, Elena Sadowsky, declined to comment on the case Friday.

Coleman is expected back in federal court on Sept. 9, according to filings. It’s unclear when his mental health evaluation will be complete.

Ciaran McEvoy, a spokesperson for the U.S. The Attorney's Office, Central District of California, declined to comment on the pending case on Friday.