At about the same time he began listening to O’Reilly, Dear also bought his first computer and went on the internet for the first time. For a mind already conditioned to the endless stream of conspiracies and hate-mongering of talk radio and Fox News, the internet was a round-the-clock source of affirmation. “He was hooked—addicted,” his son recalled. “He was all, ‘The Illuminati control the world! Contrails control your mind! The CIA started aids! Jenny McCarthy is right about vaccines! George W. and Laura Bush are both lizards!’”

Walker stressed to me that the Dears enjoyed a relatively normal family life in Walterboro. Dear sometimes played video games with him and Taylor, and he liked to ride his motorcycle with them while they rode dirt bikes or ATVs. On Sundays, Dear read the Bible with them. “He was my dad,” Walker told me. “He was really normal, except for his beliefs.”

Embedded in Dear’s anger against Planned Parenthood was a deep-seated anger against women. Dear and Ross divorced in 2001, after an incident of domestic violence. In 2005, he began posting his profile on dating sites like SexyAds.com. He was interested, according to his posts, in a “discreet relationship, casual sex, BDSM, a long-term relationship, spanking.” He was in and out of online relationships with women until 2008, when he met Stephanie Bragg.

Bragg, whom acquaintances describe as fragile and needy, was a devout Christian with two school-age daughters. After dating Dear for a year, she left her children and joined Dear in North Carolina, where he lived in an isolated shack in the woods to evade what he believed was persecution by the feds back in South Carolina.

Dear did, in fact, have trouble with the law in South Carolina, but not at the federal level. One neighbor had called the police to complain that Dear had threatened his life and shot his dog; another filed for a restraining order after he peeped in her window. Dear’s problems persisted in North Carolina, with complaints that he was abusing and neglecting his dogs.

In 2012, Colorado joined Washington to become the first states to legalize recreational marijuana use. Dear had been a regular user for years. Bragg had a prescription for medical marijuana, but her supply was apparently limited, so Dear had to buy from weed dealers, which made him nervous. He decided to move with Bragg to a remote locale in Colorado, where he could avoid federal surveillance and freely grow and smoke “herb,” his favored term for marijuana.

Frustrated by his father’s conspiracy theories and strident religiosity, Walker had fallen out of touch with his dad. Then one day, he turned on the television and saw his father on the news for the Planned Parenthood shooting. It was hard to reconcile his memories of his dad with the wild-eyed murderer being paraded before the cameras. He was especially struck by shots of Dear’s dilapidated camper. The squalor seemed like a symbol of just how much his father had changed. “Our place in Walterboro wasn’t perfect, but it wasn’t a mess,” Walker said. “We lived there.”

Those in the right-wing media who traffic in hate and conspiracy theories are quick to deny that they should be held responsible for the consequences of their words. After Waco, Rush Limbaugh took to the airwaves to predict that “the second violent American revolution” was imminent. Yet two weeks after the Oklahoma City bombing, he published an op-ed in Newsweek entitled “Why I’m Not to Blame.” After running 29 shows attacking George Tiller as “Tiller the Baby Killer” and saying there was “a special place in hell” for him, Bill O’Reilly dismissed any accountability for inciting the doctor’s murder: “I reported extensively on Tiller and after he was assassinated by a man named Scott Roeder, some far-left loons blamed me.”

AMERICA'S MADRASSA Carl Gallups It was from Gallups, a Sandy Hook “truther” who believes the school shooting was a hoax, that Dear learned that President Obama is Satan. Mandy Connell A few months before his rampage, Dear called in to Connell’s radio show, where he’d first heard about the “baby body parts” videos. Alex Jones The conspiracy theories on Jones’s web site, Infowars, fueled Dear’s delusional fears about surveillance by the federal government. Texe Marrs A shortwave radio host and favorite of Dear, Marrs claims the federal government framed Timothy McVeigh for the Oklahoma City bombing. Rush Limbaugh Limbaugh made anti-abortion rhetoric mainstream; Dear liked to tune in to his anti- government rants for hours on long drives, alone in his car. Bill O’Reilly O’Reilly’s unrelenting on-air attacks on George Tiller, an abortion doctor murdered by an extremist in 2009, had a powerful impact on Dear. CLOCKWISE FROM TOP LEFT: COURTESY PHOTO X 3; ILYA S. SAVENOK/GETTY; JUSTIN LUBIN/NBCU PHOTO BANK/GETTY; LUCAS JACKSON/REUTERS.

I contacted many of Dear’s media role models to ask if they saw any connection between the beliefs they advocated on-air and online and what Dear had done after he listened to them. Only Troy Newman, from Operation Rescue, agreed to speak with me. He denied that his group’s rhetoric had spurred Dear in any way, but he acknowledged the power of its anti-abortion message. When we talked about the Planned Parenthood videos, he said that Dear “realized there is truth here, that babies are being murdered. So he went and acted—but in a lunatic way, rather than within the system.”

But when it comes to his terrorism, Dear’s insanity is beside the point. “Forty percent of lone actors who commit terrorist acts are diagnosed as mentally ill,” says J. Reid Meloy, a professor of psychiatry at the University of California in San Diego who develops terrorist assessment tools for the FBI. “Paranoid individuals take what they hear in a very literal, concrete, absolutist way. They often don’t understand sarcasm. It can excite them to violence.”

Dear talked often about a group called Army of God, a Christian terrorist organization that has engaged in murder and kidnapping against abortion providers. He loved its web site and felt a kinship with its leaders. After the Planned Parenthood massacre, when Dear was in prison, he received a letter he said was full of praise from Donald Spitz, a spokesman for the group.

I told Dear that last spring, Army of God posted a chilling homage to him on its web site. It showed a photograph of Dear at the time of his arrest, with a caption that read, “I am a warrior for the babies!” Dear was pleased about this, but not satisfied.

“Does it say anything else?” he asked.

Dear had written to Spitz, and he was eager to know if Spitz had complied with his request to post the passage from Luke 10:18 that proved Barack Obama was Satan. When I told him it wasn’t there, he seemed annoyed, but also validated.

“Spitz is a fed,” he said. “I knew he was a fed because he said he couldn’t afford to call me. Yeah, right.”

It would be easy to dismiss Dear as an unstable man who was driven by his mental illness rather than an organized ideology. After his arrest, psychiatrists diagnosed him with a “delusional disorder, persecutory type.” But Dear’s tendency toward violence was shaped and steered by outside forces every bit as much as the foreign terrorists we have come to fear. In its calls for an anti-abortion jihad, Army of God sounds eerily similar to ISIS. “We desperately need single lone rangers out there, who will commit to destroy one abortuary before they die,” the group has declared. Terrorism respects no borders and hews to no one ideology or religion. The raw materials it needs are always at hand. All it requires is the proper vehicle to drive itself into the world.

For Dear, the right-wing media and the extremism they champion gave his delusions and rage a sense of higher purpose—one couched in a religiosity every bit as dangerous as that of Islamic fundamentalists. “I’m what you call the guys who fought the crusade,” Dear told me. “I prayed to God to let me be David from the Bible, a mighty man of valor. I prayed and he granted my wish.” The voices Dear heard came not from above, but from his radio and his television and his computer. They told him whom to think of as evil. They told him whom to hate. “That’s the only reason I had the strength to do what I had to do,” he says. “I’m nothing special.”

This article was reported in partnership with The Investigative Fund at The Nation Institute.