Matthew Taylor Coleman.Photo: Instagram

In the months beforeMatthew Taylor Colemanwas arrested for allegedlykilling his two childrenwith a spearfishing gun in Mexico, the father of two spent an increasing amount of time online looking at conspiracy theory websites and message boards, a family friend tells PEOPLE.
“It was obvious that he was spending a lot of brainpower on it,” the friend, who has known Coleman since they were children, says. “He was constantly checking those sites on his phone. He spent hours each day just glued to his phone looking at that stuff.”
While the friend does not know the exact websites and message boards that Coleman visited, he says that he would talk about the QAnon theories in casual conversation. “He’d read me things off his phone and say, ‘Listen to this one.’ And then he’d show me other posts of other people who believed the strangest things.”
Police say Coleman drove the children into Mexico. Two days later, authorities allege, he took the kids to a ranch, where hekilled them with a spearfishing gunand returned to his hotel a few hours later. He was arrested when he attempted to cross the border back into the United States.
Kaleo and Roxy Coleman.Matthew Taylor Coleman/instagram

“M. Coleman stated that he believed his children were going to grow into monsters so he had to kill them,” Bannon wrote.
Want to keep up with the latest crime coverage? Sign up forPEOPLE’s free True Crime newsletterfor breaking crime news, ongoing trial coverage and details of intriguing unsolved cases.
Coleman wasindicted on murder chargeslast month. If convicted, he is eligible for the death penalty. Coleman is now being held in protective custody. He has not yet entered a plea, and the public defender’s office has not returned PEOPLE’s calls for comment.
“It was an obsession for him” the friend says. “But no one knew how serious it was. Now I wish I had pushed back a little more and maybe stopped a tragedy.”
source: people.com