How The Feds Brought Down Arizona’s Suspected White Supremacist ‘Serial’ Bombing Brothers

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In a small trailer park in Catoosa, Okla., in 2005, an aging white supremacist made a startling claim to a woman he had met only earlier that day.

He told her he was a serial bomber.

According to federal court records, Dennis Mahon, was thumbing through an album of old pictures for the woman, showing off his Ku Klux Klan robe and other artifacts of his life when he began to tick off a list of places he claimed to have bombed since the early 1980s.

There was an abortion clinic, a Jewish community center and offices of the IRS and immigration authorities. He told the woman he liked to use a mixture of ammonium nitrate and fuel oil. He said he added powdered sugar to the mix for an extra bang. He would set off the bombs at 2 a.m., he said, so that no one was hurt but a message was still sent.

What Mahon didn’t know was that the woman he was bragging to was an informant working for federal law enforcement. And the trailer she was staying in was rigged with hidden cameras and microphones to catch every word.

Today, the former KKK leader and his twin brother, Daniel, are scheduled to go on trial in federal court in Phoenix, thanks to the conversations they had with that informant, Rebecca Williams, over four years.

The twins are accused of sending a mail bomb in early 2004 to a government diversity office in Scottsdale, Ariz., injuring the office’s director and two of his employees. Both are charged with conspiring to blow up a government building while Dennis Mahon is also charged with carrying out the bombing as well as teaching someone else how to make a bomb.

The case is extraordinary for many reasons, not the least of which is that it may be the first time federal investigators have been able to seriously infiltrate a network of so called “lone wolf” extremists, a loose-knit group of racists and anti-government types who seem to always be looking for ways to start or win an ever-coming race war. It’s the same type of network that produced Oklahoma City bomber Timothy McVeigh.

Led by a veteran investigator with the Bureau of Alcohol, Tobacco, Firearms and Explosives, the probe into the Mahon twins also targeted Tom Metzger, one of the preeminent leaders of the white supremacist movement in the US, as well as Robert Joos, a Missouri survivalist who stockpiled weapons in caves on his farm near the Ozarks.

“It’s certainly one of those high water mark cases,” said the director of the Arizona office of the Anti-Defamation League, Bill Straus, who has followed the case since its inception. “It reminds the community that guys like this, guys that created and sent that bomb are a threat to the entire community. Period.”

It all began on Feb. 26, 2004 when a cardboard box arrived at the Scottsdale Office of Diversity and Dialogue. It looked like a perfectly normal package, with $3.95 postage paid. It was addressed to the office’s director, Donald Logan. When he opened the box, it exploded, tearing flesh from his arms and nearly costing him his fingers. His assistant, Renita Linyard, was also seriously injured. Another staffer in the office, Jacque Bell, suffered minor injuries.

Scottsdale police immediately called the ATF in for help. The federal agency had more resources and reach to investigate a bombing. The agency put special agent Tristan Moreland in charge of the case. A smart, dedicated investigator in the agency’s Arizona office, Moreland had worked on some of the toughest cases in the state, often going undercover to solve them.

Given the target’s job and race — he is black — Moreland and his team began looking at extremist groups that may have had ideological reasons to carry out the attack.

They didn’t need to look far. A national gathering of white supremacists, neo Nazis and KKK members had taken place just a few weeks earlier at a park about 10 miles north of the city. The event was called Aryanfest 2004.

Dennis Mahon was in attendance, bragging about having known the Oklahoma City bomber. Metzger was there, too, acting the part of an elder statesman.

Metzger ran a group called White Aryan Resistance, or WAR, and was well known in extremist circles. The group has since changed its name to The Insurgent. Metzger is a proponent of “lone wolf” tactics, encouraging his fellow racists to carry on the struggle by themselves or in small cells to avoid exposing the rest of the movement to law enforcement. Mahon was once an organizer for WAR and had been friends with Metzger for decades.

Their attendance at the festival wasn’t the only thing that aroused suspicion. Five months before the bombing, Mahon had called the Scottsdale diversity office and left a disturbing voice mail about the city’s Hispanic heritage week. It was bad enough for the office to call police and report it.

“You guys, you, you, rich white people you really, you really are something else. If, if I had my way I’d sic about hundred thousand illegal aliens right into Scottsdale and see how you like your damn heritage,” Mahon said in the message, according to court records. “The White Aryan Resistance is growing in Scottsdale. There’s a few white people who are standing up. Take care.”

The ATF decided to take a closer look at Mahon and Metzger. The investigators discovered that Mahon and his twin brother had been living in a trailer park in neighboring Tempe, Ariz., in the months before the bombing, but the pair packed up and left just a couple weeks after it occurred.

In the following months, Moreland was able to track the Mahon brothers to the trailer park in Catoosa. But without the ability to get closer, the investigation would have gone cold.

That’s when Moreland decided to have someone go undercover and befriend the brothers. According to court records, in January 2005, Moreland began looking for a confidential informant — a civilian — who would be willing to devote a lot of time to the operation.

Someone else in federal law enforcement pointed him to Williams. Federal court records say very little about her background. She had no real training and had only worked on one previous case. But she was an attractive woman, 20 years younger than the Mahons who seemed to have the wherewithal to handle herself around dangerous people.

In a hearing in September 2010 in federal court in Phoenix, Williams described her job in simple terms. “Just to get information.” The ATF’s plan was to put Williams and an undercover female ATF agent in a trailer near the Mahons at the Catoosa trailer park.

On Jan. 26, 2005, the pair drove the camper, rigged with cameras and microphones, into the park. While setting up in a space, the women placed a confederate flag in a window of the trailer.

Before long, the Mahon brothers came over and introduced themselves.

“I’m a girl and they’re guys and, you know, guys like to talk to pretty girls so they –we just started talking,” Williams said at the 2010 court hearing.

Over the next 10 days, Williams paved the way for a relationship with the brothers that lasted the next four years. She was integral to the investigation, and almost every moment of her interaction with them was recorded by law enforcement. Her pickup truck was wired with cameras and microphones. She kept a microphone on her key chain.

Dennis Mahon bragged about the serial bombings early on, and his brother seemed to verify some of it. Daniel Mahon told her about drive-by shootings and car bombings, according to the court records.

“We thought we were doing the right thing. We were just trying to send a message,” Daniel Mahon told Williams. “When I would take someone’s car out, it wasn’t anger. It was a sense of duty. It is like a military operation. You plan for it, equip for it.”

Williams often egged the brothers on. In one conversation, she asked Dennis Mahon if he ever had any success with sending a package bomb to someone.

Court records say he leaned in close and whispered, “In Tempe, Arizona, Goddamn diversity officer, Scottsdale Police Department, had his fingers blown off.” He then caught himself, paused and told her that he had advised “white cops how to do it.”

It’s clear from the court records that Dennis Mahon liked talking to Williams. He developed a strong emotional and physical attraction to her.

ATF and Williams used this to their advantage. In one example, Williams testified that the investigators got her to pose for photographs wearing a bathing suit with a grenade hanging down from her neck in between her breasts. For the pictures, she stood in front of a pickup truck and a swastika flag. The photos were then mailed to the brothers.

Throughout the investigation, Williams and the ATF were able to document close ties between the Mahons and other extremists, with WAR’s Metzger being the most prominent of them. They were also able to gather enough evidence to make arrests.

On June 25, 2009, agents executed search warrants in three states. They searched the Mahons’ house in Illinois, Metzger’s house in Indiana and the Missouri farm owned by Robert Joos. They arrested Joos on suspicion of weapons charges and the Mahon twins on suspicion of the bombing.

Joos was later convicted and sentenced to six and a half years in federal prison. Metzger, however, remains free. Federal prosecutors never accused him of a crime.

In a recent interview with TPM, Metzger said the ATF let him go him because he hadn’t done anything wrong. He said he didn’t think the Mahons were involved in the bombing, either.

“I have a hard time believing that they did it,” Metzger said by phone from his home in Indiana. “I’ve always cautioned them against going across the line.”

Attorneys for the Mahons did not return phone calls seeking comment. However, in court filings, they’ve criticized the government’s case, saying the informant’s interactions with the twins were “outrageous.”

In 2010, the attorneys asked Judge David Campbell to throw out some of the charges because of the conduct. But the judge declined, saying he would leave those decisions to the jury.

What’s not clear from the investigation is how serious the Mahons were about their claims of long-ago bombings and shootings. At a hearing in 2010, Moreland, the lead ATF investigator, said he looked into the claims. He told the court he could never develop enough evidence to either prove or disprove them.

As for Don Logan, the target of the bombing, he told TPM he’s glad the trial is starting, even though it’s been almost eight years since the explosion.

“I obviously have been waiting a long time for this day to finally come,” Logan said on Monday. “It’s time to move to the next level.”

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