'We were infiltrated, mom': Secret recordings track demise of domestic terror attack

This is part 2 of a three-part ABC News series looking at one chilling case of right-wing extremism in America’s heartland. Part 1 is available here and part 3 is available here.

Patrick Stein, Curtis Allen and Gavin Wright, three Kansas militia men determined to kill Muslim refugees in the small town of Garden City, Kansas , spent months trying to choose a target.

They met regularly at Wright’s business, G&G Mobile Home Center, rattling off possible victims, while a fourth man they recruited, Dan Day, critiqued their ideas and offered his own views.

What they didn’t know at the time was that Day was working for the FBI and secretly recording the meetings.

In a series of exclusive interviews with ABC News' George Stephanopoulos, Day and his family described what they endured for months, as Day tried to stop an attack slated for the day after the 2016 presidential election. Day's story is featured in the new ABC News documentary “The Informant: Fear and Faith in the Heartland,” now available on Hulu .

ABC News obtained a cache of the recordings Day made, offering a rare, real-time look at what it takes to stop a terrorist plot fueled by hatred and hysteria.

“Ask yourself, would you be willing to do what he did?” Robin Smith, one of the FBI agents who ran the case, said of Day. “Would you be willing to risk what he risked?”

‘Anything that will kill and maim’

When the group’s hunt for a target began, they used GoogleEarth to find potential victims.

“Drop pins every location where we know them bastards are at. … Then print it off, you got a map,” Stein said at a recorded meeting in early August 2016.

One of the locations they marked was a single-story apartment complex at 312 West Mary Street, where more than 100 people, almost all of them from Somalia, lived and even more prayed each day inside an apartment converted into a mosque there. Stein and Day had previously scoped it out.

When it’s not too windy or too cold outside, the complex blooms with “people playing and barbecuing,” said Ifrah Ahmed, a Somali refugee and leader in Garden City's Muslim community. “Typical American life.”

One resident there was a woman in her late 50s, who was blinded as a teenager when al Qaeda-linked terrorists detonated a bomb in Somalia. Another resident was a young mother who had just given birth to a boy named Samir.

“Cockroaches,” Stein called them, using his favorite term for anyone who’s Muslim.

The FBI wanted Day to nudge the group to pick the apartments and mosque at 312 West Mary Street as their target. The complex was close to the FBI office, making it “easier” for the FBI to scramble there if necessary, according to agent Amy Kuhn, Smith’s partner at the time. So Day promoted it.

“I’d take out that mosque,” Day told the men in mid-August 2016, as his hidden device recorded. “It’s just a brick and frame building, kind of like a house.”

Eventually, the men settled on that West Mary Street apartment complex as their target.

They also finally concluded that a bombing would be best.

“We’re gonna … be putting [in] nails, ball bearings, goddamn sheet rock, knife blades,” Stein said in early September 2016.

“Anything that will kill and maim,” Wright added.

A crisis of conscience

Day said he constantly “struggled” with his role as an FBI informant.

He regularly worried that someone may have followed him home at night or figured him out some other way. Day said that early on, Allen had pointed a gun at him and warned, “Anybody finds out about [us], I’m gonna put a bullet in your head.”

Day placed firearms around his house and adopted a pit bull as a security dog. He spoke with his family about what could happen to him, or them.

He was also in harm’s way at G&G. Because the business was in such a remote area, an hour outside Garden City, the FBI couldn’t send surveillance teams as backup without them being noticed.

“There was no one there to swoop in if something goes wrong,” noted former federal prosecutor Tony Mattivi, who oversaw the case.

But it wasn’t just the danger that daunted Day. It was also “hard” for him to spew so much hate, he said. By the time the group started meeting at G&G, Day had already spent nearly five months with them.

“I had to be like them, talk like them,” Day said. “I'm not proud of it.”

On one recording, when Stein touted his “cockroach theory” that to eradicate Muslims “you can’t just kill one, you gotta kill every one of them.”

Day assured Stein, “It’s going to be famous.”

Day’s wife of 28 years, Cherlynn Day, said she remembers asking her husband one night: “Do you really believe them?”

“It was going on for so long and … we were afraid that’s what [he] was becoming,” she said.

The FBI’s ‘Oh s---’ moment

During a meeting inside the trailer at G&G, Wright warned the group they should try to make their own bombs, because buying explosives meant “you’re gonna get set up.”

For weeks, Wright and Allen tried to manufacture the explosive substance needed to set off a bigger bomb. Wright printed out nearly 1,000 pages of manuals he found online, and Allen watched instructional YouTube videos.

“They ordered stuff. They had all the materials,” Day said. “They were experimenting.”

Then, in mid-September 2016, Wright and Allen showed up to a meeting downright giddy. They had successfully made their own explosive, and tested it.

“I could feel the percussion of it,” Wright said with a laugh. “That was f---ing awesome.”

For the FBI and federal authorities, “That was our, ‘Oh s---,’ moment,” Mattivi said. “We had these guys saying on tape that they had manufactured an explosive. … That was when I started losing sleep.”

Sounds ‘like a CIA setup’

The group’s plot was developing faster than the FBI expected, and Day “was petrified of continuing to work as an informant,” Mattivi said. “But he felt like there was no way he could stop.”

The FBI decided it was time to introduce an undercover agent into the operation -- someone who could “get them away from making their own explosives” and help the FBI control the plot, Kuhn said.

Under the FBI’s direction, Day told the group at G&G one day that he had ties to gun-running criminals in Oklahoma with access to “anything,” even bombs. Day had vaguely mentioned such connections to Stein months earlier, so it wouldn’t have seemed out of the blue to Stein.

“[These] guys, they’re the real deal,” Day is heard insisting in one of his recordings.

Wright liked the idea of acquiring a bomb from someone Day knew and trusted: “That beats making it unless we have to,” Wright said.

Allen was skeptical.

“It just sounds weird,” he said on one recording. “It’s starting to sound like a CIA setup.”

Stein, though, was eager to move forward with the plot, so he volunteered to rendezvous with Day’s “connections.”

The ‘bromance’

In late September 2016, Day brought Stein to the middle of another Kansas field to meet “Brian,” an undercover agent who Mattivi said looked like a “burly, bearded man’s man.”

“Well,” Brian said to Stein, “I wanted to meet you [because] … I ain’t gonna give it to no jihadis to go blow up people I care about.”

“I’m, uh, glad to hear that actually,” Stein responded. “Because that’s exactly what this is going for. … To take [Muslims] out.”

“I’m cool with that, man,” Brian said.

The meeting was relatively uneventful, but wildly successful. Stein and Brian hit it off even more than the FBI expected.

“They established a bromance,” Kuhn recalled with a smile.

They began texting each other almost daily about the “cockroaches,” the coming “war,” and “love of country.” They exchanged “LOLs” and “attaboys.”

Stein even revealed to Brian that he’d decided on a date for their attack: Nov. 9, 2016, the day after the presidential election in six weeks.

“[I]f we were to do this now this close to the election I am scared that it would give a lot of ammunition to the Hillary [Clinton] supporters,” Stein wrote in a text message.

“Bro, that is a great line of thinking,” Brian responded.

Stein also mentioned to Brian that he had “close to 300 pounds” of extra fertilizer on his farm.

“We could use that,” Brian said, suggesting they build “vehicle-borne” bombs with it.

Stein grew gleeful at the idea of such a big bombing: “I’d give anything to have a camera set up that would WiFi that s--- to me so I could watch it live,” he said with a chuckle.

They agreed to meet up again in the coming days, so Stein could deliver the fertilizer to Brian.

Another ‘Oh s---’ moment

But then Allen’s girlfriend called local police.

She accused him of domestic violence, and told police, “Oh, by the way, he's a member of a militia, and he's planning to do something,” Kuhn recalled.

Unaware that the FBI had been tracking the group for months, local police scrambled to G&G and arrested Allen on domestic abuse charges. Smith briefed local officials on the federal probe.

“That's another sort of ‘Oh s---’ moment for [the FBI],” Mattivi said, explaining that Allen’s arrest could have pushed Stein and Wright to “hurry up and commit a different act of violence,” or could have at least stymied the FBI investigation.

After all, according to Mattivi, Wright warned Stein to scrap his next meet-up with Brian.

“I didn't think he'd go through with it,” Mattivi said of Stein.

But then “much to my surprise, and the surprise of a few others, Patrick [Stein] actually shows up,” Mattivi recalled. “That’s where the bromance kicks in, because Patrick says, ‘Oh, there’s no way Brian’s a cop.’”

The takedown

Three weeks before the 2016 presidential election, Brian and Stein met inside a local McDonald’s restaurant. In the bed of Stein’s pickup truck were six 50-pound bags of fertilizer, for car bombs.

“It’ll be two vans,” Brian told Stein. “It’s gonna make a big mess. … I mean, I’ll be honest with you, there are a bunch of kids there.”

“I’m sure there are,” Stein responded.

Then Stein emphasized one thing: “I’m putting my faith in Dan on this deal. Literally, I mean my whole life rides on it.”

When they stood up from the table and walked outside to the parking lot, a SWAT team surrounded them with guns drawn, yelling at them to get on the ground.

Moments later, an FBI team arrested Wright at his home in Oklahoma, just over the Kansas border. Allen was already in police custody for alleged domestic abuse.

When the FBI searched their homes, vehicles and offices, they found buckets of bomb making materials, a finished detonator and drafts of a manifesto.

“Don’t be fooled by the words ‘conspiracy theory’ or ‘domestic terrorist,’” one of the drafts said. “All this is a word game, ‘brainwashing’ by our government.’”

“I think most people would read that manifesto and think, ‘Whoever wrote this is nuts,’” Mattivi said.

After Stein was transported to a county jail, he called his mother with an urgent message for the Kansas Security Force.

“’Dan Day, D-A-Y, is a g----mn fed.’ … get the message out,” Stein told his mother during a recorded call. “We were f---ing infiltrated, mom.”

What could have been

The first time FBI agents Kuhn and Smith met Stein was in an interrogation room the day of the arrests.

“I’m a patriot, bro. I love my country,” Stein told them. “You don’t give a f--- about your country.”

“The amazing thing about the United States of America, and the Constitution that we live under, is you’re entitled to that opinion, and … I won’t kill you because you believe differently than me,” Smith responded.

The bombing in Garden City “would have completely shaken the foundation of America,” Smith, who retired last year, told ABC News.

Halima Farah was one of the Somali refugees living at the apartment complex at the time.

“If the bombing actually happened, maybe I wouldn’t be here,” she told ABC News. “And he wouldn’t be here,” she said, hugging a neighbor’s young son.

Based on an FBI analysis, Mattivi said what Stein planned “would have leveled that apartment building and almost certainly killed every single man, woman and child in it,” leaving behind a “level of carnage” potentially greater than the Oklahoma City bombing in 1995, when 168 died and hundreds more were injured.

Convicted and sentenced

After a five-week trial in 2018, featuring a squad of Justice Department prosecutors and five days of testimony from their star witness, Dan Day, a federal jury convicted Stein, Wright and Allen of terrorism- and civil rights-related charges.

The jury – and more recently a federal appeals court – rejected claims by their attorneys that Day and the FBI “pushed” the men “down the path that would lead to action, arrest, and chargeable offenses,” as Stein’s attorney put it.

The attorneys also claimed that nearly $33,000 the government paid Day, who was out of work at the time, incentivized Day to cultivate the plot. But Day strongly disputed that, telling ABC News, “I could’ve made more money working at McDonald’s.”

Mattivi said that -- considering the amount of time Dan spent as a government informant and trial witness -- "you work it out to an hourly basis [and] I'm not sure it was even minimum wage."

Allen and Wright were each sentenced to at least 25 years in prison. Stein was sentenced to 30 years behind bars.

In handwritten letters from federal prison in Beaumont, Texas, Stein told ABC News the public is “only hearing the government’s version of things,” which “make me look as horrible as possible.”

“I’m not going to say there isn’t some truth in what you’re reading about me and the case – kinda hard to deny actual recordings,” he wrote. “What I will say is that there is a WHOLE LOT MORE to the story than has ever come out.”

He didn’t elaborate.

‘The heart of a hero’

As terrifying as his ordeal was, Day said what he went through shows “you don’t have to be friends” with people who are different, “but you don’t have to hate them” either.

He said he has only one regret: “That [his family] had to go through the things that they did.”

Over a game of Monopoly one night, Day’s college-age daughter told her “old man” not to regret anything, because what he did saved lives.

“No one else had to suffer, and we're coming out on top,” Alyssa Day said, even as she acknowledged the experience has affected her dad in “negative ways too.”

Day believes he suffers from post-traumatic stress disorder, and he said nightmares of mayhem and mangled babies still haunt him at times.

Ahmed, the leader in Garden City's Somali community, described Day as "one of the things that make America great."

"He put his family, himself, in jeopardy for us," she said. "He saw that humanity comes first, and he saw that we were beyond what they described us to be. We were not just mere cockroaches."

“Dan Day is just an average guy who, when confronted with a situation that he didn't want and he didn't ask for, dug down deep and found the heart of a hero,” said Mattivi, who retired last year and, as a Republican, is now running to become the next attorney general of Kansas.

Day rejected the notion that he’s any kind of hero.

“It wasn’t just me. It was a lot of the FBI, and God,” he said.

To understand how Stein, Wright and Allen were driven to such extremes, read the next part of this exclusive series from ABC News: “Becoming a domestic terrorist: How 3 self-styled 'patriots' were led to lethal plot.”

ABC News' Cho Park, Eamon McNiff, Jennifer Joseph and Chris Donovan contributed to this report.