People.com Crime Matthew Coleman's Family Members 'Believe He Had a Psychotic Break' and Are Standing by Him: Source Matthew Taylor Coleman, 40, is accused of killing his 2-year-old son and 10-month-old daughter in Mexico on Aug. 9 By Steve Helling Published on September 14, 2021 10:45 AM Share Tweet Pin Email It has been just over one month since Matthew Taylor Coleman was arrested for allegedly killing his two children — and his family is still processing the tragic events. "At this point, we all believe that he had a psychotic break," a longtime family friend tells PEOPLE. "It's the only explanation that makes any sense to us. Something clicked, and he did something that was incomprehensible. Before August 7, we thought his life was damn near perfect." But the illusion of a happy family shattered that day, when Coleman and his wife, Abby were packing for a family trip. Authorities allege that Coleman abruptly put his two kids — Kaleo, 2, and Roxy, 10 months — into his van and drove away from their Santa Barbara, Calif., home. Calif. Surfing Coach Accused of Stabbing Children to Death in Mexico Is Arrested Trying to Return to U.S. Matthew Taylor Coleman. Instagram Police say Coleman drove the children into Mexico. Two days later, authorities allege, he took the kids to a ranch, were he killed them with a spearfishing gun and returned to his hotel a few hours later. He was arrested when he attempted to cross the border back into the United States. Matthew Coleman's Wife Wants to Meet with Him and Get Answers About Children's Alleged QAnon-Inspired Murders According to an FBI criminal complaint which was obtained by PEOPLE, Coleman allegedly told police he was motivated by the QAnon conspiracy theory, which holds the false belief that former president Donald Trump has secretly been battling a cabal of Satan-worshipping pedophiles at the highest levels of political power and influence. Want to keep up with the latest crime coverage? Sign up for PEOPLE's free True Crime newsletter for breaking crime news, ongoing trial coverage and details of intriguing unsolved cases. Matthew Taylor Coleman/instagram In the criminal complaint, FBI special agent Jennifer Bannon wrote that Coleman claimed to be "enlightened by QAnon and Illuminati conspiracy theories and was receiving visions and signs revealing that his wife, A.C., possessed serpent DNA and had passed it on to his children." 'I Trusted Him with My Kids': Parents of Matthew Coleman's Students React to His Arrest for Killing Children "M. Coleman stated that he believed his children were going to grow into monsters so he had to kill them," Bannon wrote. Coleman was indicted on murder charges last week. He is eligible for the death penalty. Coleman is now being held in protective custody in an undisclosed federal prison. He has not yet entered a plea, and the public defender's office has not returned PEOPLE's calls for comment. For now, Coleman's family and friends are supporting him, and hoping for answers. "We don't know what the future holds," says the longtime family friend. "And we're not endorsing anything he might have done, and we're still grieving the senseless loss of Kaleo and Roxy. But we're standing by him as this goes ahead. The hope is that he'll get the help he clearly needs."