Matthew Coleman also said that he knew what he did was wrong but that “it was the only course of action that would save the world," Daily News reported.
Coleman, 40, who is a surf instructor in California, allegedly killed his 2-year-old son and 10-month-old daughter in Mexico on Aug. 9.
He was arrested two days later.
Coleman was being held at an undisclosed federal prison on Friday, according to the Daily News. A psychiatrist is reportedly working to determine whether he is fit to stand trial, according to People.
Coleman allegedly told the FBI investigators 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 onto his children," according to a criminal complaint filed in Los Angeles federal court. He also allegedly said he was "saving the world from monsters."
Coleman’s arrest came after the bodies of his children were discovered by a farmworker in the brush near the entrance of the Rancho Del Descanso community, near Rosarito, Mexico, about 35 miles south of the U.S.-Mexico border, the Baja California Attorney General said during a press conference.
Both children, who were U.S. citizens and from Santa Barbara, were covered in stab wounds, authorities said. His daughter had been stabbed 12 times and his son had been stabbed 17 times, according to police. A sharp wooden stake that was believed to have been the weapon was found at the scene, NBC San Diego News reported.
The Santa Barbara Police Department said that on Aug. 8 officers took a missing persons report from a woman who reported her husband and two children missing for approximately 24 hours. During their investigation, police uncovered evidence that the father of two had possibly traveled to Mexico, KSBY reported.
A judge ordered Coleman be held without bond. He is due back in court for arraignment on Tuesday. Coleman has not yet entered a plea in his case.