Matthew Taylor Coleman was supposed to go on a camping trip with his wife and their two young children last weekend. But evil was in his midst and threatened to bring about the end of the world, he told investigators.

He had to do something.

So, with sunrise still an hour away on Saturday morning, Coleman loaded his two children — a 2-year-old son and a 10-month-old daughter — into a Mercedes Sprinter Camper Van, an FBI agent said in court documents filed Wednesday. Coleman didn’t have a car seat for his daughter, so he put her in a box.

From his home in Santa Barbara, Calif., Coleman drove south, investigators say.

Instead of the family camping trip he had planned, Coleman took his children some 250 miles to Rosarito, a resort city on the Pacific coast in Mexico, just south of the U.S. border, FBI agent Jennifer Bannon said in a nine-page sworn affidavit. Then, he shot each of them in the chest with a spearfishing gun, the agent said.

On Wednesday, federal authorities charged Coleman, 40, with the foreign murder of U.S. nationals. Court records did not list an attorney for Coleman.

After Coleman left home on Saturday, his wife called Santa Barbara police to report that her husband had taken their children and wasn’t answering her text messages, Bannon said in her affidavit. The wife, identified as “A.C.” in the document, told the officer she did not believe her husband would hurt the children or that they were in any danger. She said Coleman would eventually return, and when the officer offered to meet her in person, she declined.

The next day, she called back. That evening, an officer went to her house. She told him that she and Coleman had not been having problems generally, nor had they had an argument that might have precipitated him taking the children, the affidavit states. But she officially reported them missing.

On Monday, two days after he left, Coleman reentered the United States without the children. Federal agents detained him, noting what appeared to be blood on his van’s registration papers, court records state.

An FBI agent interviewed Coleman, and he confessed to killing his children, Bannon said in her affidavit. Coleman said he had been enlightened by the extremist group QAnon and the Illuminati, both baseless theories that claim secret elites are maliciously controlling national and world affairs from the shadows. He had received visions and signs revealing his wife “possessed serpent DNA,” which she passed on to their children, according to the affidavit.

By killing them, he allegedly said, “he was saving the world from monsters.”

“He knew it was wrong, but it was the only course of action that would save the world,” Bannon wrote in her affidavit.

Afterward, Coleman said he moved the bodies about 90 feet away to put them in some brush, Bannon said.

The killings are not the first alleged crimes connected to QAnon, which the FBI has deemed a domestic terrorism threat, or similar ideas that precede it. In 2016, a man drove from North Carolina to Washington, D.C., with a plan to rescue children supposedly being abused by members of the Democratic Party — false claims known as Pizzagate — from a popular restaurant in the city’s Northwest.

A person claiming to be an intelligence official who posted anonymously as “Q” online continued spreading that type of false information, claiming that satanic pedophiles drank children’s blood to stay young.

Followers, who became known as QAnon supporters, later appeared at rallies for President Donald Trump. Some devotees also took part in the Jan. 6 Capitol riot, claiming that the “#Storm” Q envisioned on far-right message boards had arrived.

Court records provide few details on Coleman’s alleged interest in QAnon and the Illuminati. Born and raised in Santa Barbara, Coleman learned to spearfish and sail as a boy, according to the website for his company, Lovewater Surf, which offers lessons and rentals in Santa Barbara.

But it was surfing that became his passion, the website says. He competed on the surf team for Point Loma Nazarene University when he was an undergrad. He then moved to Spain, which served as a launchpad for a “surf mission” to more than 20 countries around the world, the site adds.

When Coleman returned to Santa Barbara two years later, he spent the next decade teaching high school, coaching a surf team and working at a nonprofit that used surfing to mentor kids, Lovewater’s website says.

In 2017, he married his wife, and the two founded the surf school, according to the website and Coleman’s Instagram account. The following year, they had their first child: a baby boy, his social media posts show. In September 2020, a girl followed.

Coleman’s accounts show a middle-aged father vacationing and surfing with family and friends. A video he posted on July 16 shows him catching a wave and hopping up on his surfboard, before pulling up his toddler son as they cruise toward shore.

The caption: “Baby steps!”

In May, Coleman posted a photo of himself beside his wife, as he held their son and she held their daughter — all of them on a beach and flanked by the sea.

That caption: “My treasures!”