This undated PennDOT identification photo released Tuesday, Sept. 16, 2014, by the Pennsylvania State Police shows Eric Matthew Frein, 31, of Canadensis, Penn., being sought in Friday's shooting that left one trooper dead and another critically wounded at a state police barracks in Blooming Grove. A gunman killed Cpl. Bryon Dickson, 38, and critically wounded Trooper Alex Douglass outside the barracks during a late-night shift change, then slipped away. (AP Photo/PennDOT via Pennsylvania State Police) Eric Matthew Frein, 31, of Canadensis, Pa. (AP Photo/PennDOT via Pennsylvania State Police)

The man alleged to have shot two Pennsylvania police officers on Sept. 12 stalked them on a cool night under a gibbous moon. He hid in woods at the edge of game lands in rural Blooming Grove, Pa. And, at around 10:50 p.m., he fired, killing one man and seriously wounding another.

Eric Matthew Frein, 31, of Canadensis, Pa., has been charged with this inexplicable crime. But state police said he has a philosophy: survivalism.

What is it?

In short: a stark worldview that fuses, in varying degrees, millennialism, Second Amendment and hard-money advocacy, environmentalism and racism. It’s an ideology with many godparents, including Henry David Thoreau, Ludwig von Mises and Charlton Heston. And its proponents think the world as we know it will end soon — and we must be prepared.

Hence their nickname: “preppers.”

We’re living in a time of instability,” one told Emily Matchar, who wrote for Outside magazine. “It doesn’t take long for people to turn into animals.” (For the record: Matchar wrote preppers “don’t like being called survivalists — that word has dark, kooky connotations.”)

Another definition of survivalist from survivalist.info: “One who has personal or group survival as a primary goal in the face of difficulty, opposition, and especially the threat of natural catastrophe, nuclear war, or societal collapse.”

For survivalists, Armageddon comes in many flavors. Nuclear war. Famine. Oil crisis. Plague. U.S. dollar crash. Black-on-white race war. And zombies.

Something is coming, whatever it is.

“The biggest problem we suffer here in North America is complacency,” a prepper told CBN in 2012. He added: “People figure since nothing has happened in ‘x’ amount of years, nothing bad will ever happen. So they get comfortable, and they get lazy and then unpreparedness comes in. Then you have other people who look at history.”

After a 20th century filled with horror and uncertainty — genocide, the Cuban Missile Crisis, the oil embargo, AIDS, Y2K — some prepper plans are downright advisable, if not quaint.

Make a plan to can,” reads one post on americanpreppersnetwork.com called “5 Ways to Get Ready for the Fall Harvest. “When it’s time to harvest each plant, set aside a day and be prepared to pull food from the garden.” 

Some are more intense.

Be armed and know how to use your weapon of choice,” advised a post on theorganicprepper.ca dissecting riots in Ferguson, Mo., this summer after the killing of 18-year-old Michael Brown by police. It continued: “Whatever your choice of weapon, practice, practice, practice. A weapon you don’t know how to use is more dangerous than having no weapon at all.”

And some are really, really, really intense. Consider the family bug-out plan of Braxton Southwick, who appeared on the reality show “Doomsday Preppers” — once National Geographic’s highest-rated show — as recounted to Josh Eells of Men’s Journal:

“If they get 9-1-1 three times, they know to come home immediately,” he says. (In case phone lines are down, they also have walkie-talkies.) Wearing gas masks, the clan will grab their guns and start loading their caravan: son Treston in the back; Braxton in the middle, towing an RV; son Braxton Jr. up front, driving Braxton’s old racing truck, in case they need to ram through roadblocks. “It sounds crazy, doesn’t it?” he says, shaking his head.

Preppers resist classification — and, for that reason, are hard to dismiss. Investment adviser and onetime Libertarian Party presidential candidate Harry Browne, who wrote books with titles such as “Fail-Safe Investing” as well as “How I Found Freedom in an Unfree World,” was linked to survivalism. But so was Oklahoma City bomber Timothy McVeigh. And survivalists have murdered police officers before, as the Southern Poverty Law Center pointed out.

It’s not yet clear what brand of survivalism Frein, an alleged killer, subscribed to. But he seems less an economist than a psychopath.

“He has made statements about wanting to kill law enforcement officers and also to commit mass acts of murder,” Pennsylvania State Police Commissioner Frank Noonan said on Tuesday. “What his reasons are, we don’t know. But he has very strong feelings about law enforcement and seems to be very angry with a lot of things that go on in our society.”

Pennsylvania police labeled Frein, a trained marksman, “extremely dangerous.”

According to his father, he “doesn’t miss.”

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