A man arrested on suspicion of stabbing his two young children to death was 'influenced by QAnon and Illuminati conspiracy theories'.
Matthew Taylor Coleman, 40, has been accused of murdering the toddlers with a wooden stake.
The 40-year-old, of Santa Barbara, California, was detained on Monday by US Customs and Border Protection agents tying to cross the US-Mexico border.
The children's bodies were found on a farm on Monday morning, police say.
Surf instructor Coleman said "he believed his children were going to grow into monsters so he had to kill them," according to the court document.
He had traveled with his son Kaleo, three, and ten-month-old daughter Roxy to Rosarito, Mexico.
The dad checked into a City Express hotel room on Saturday, local news reports say.
Video footage showed them leaving in the early hours of Monday morning, Mexican authorities said.
CCTV shows him returning later on Monday without the children.
He confessed to the FBI during an interview that he had taken their lives.
The children's mother Abby Coleman reported them missing 24 hours earlier.
The FBI agent said "He explained that he was enlightened by QAnon and Illuminati conspiracy theories and was receiving visions and signs revealing that his wife possessed serpent DNA and had passed it on to his children."
Hiram Sanchez Zamora - with the Baja California AG's office - said a farmhand discovered the bodies.
The worker saw splattered blood on the ground at property near El Descanso ranch.
The boy had been stabbed 17 times, and the girl was stabbed 12 times, officials say.
The worker, who wanted to remain anonymous, told Border Report: "To be honest I teared up. And I immediately notified my manager to call the police to come investigate.
"I was scared and sad because these are tiny children who don't know any better. Hopefully they find whoever is responsible because this is a terrible thing."
Coleman is expected to be extradited to face murder charges over the next few days.
The family's neighbours told CBS LA of their shock - and said Coleman "seemed like a good family man". One called it "immensely tragic".
Coleman posted frequently about his Christian faith online before the deaths.
In November 2020 he wrote on Facebook : "There is a type of Great American Renaissance following the years of Covid, censorship, and political divisiveness... that will empower each person's heart to come alive and explode with innovative ideas, new business models, new music sounds and never seen ways to build an amazing community?"
