FBI says 18-year-old ISIS follower plotted ‘flaming sword’ attacks on local churches

An Idaho man who once “drank the kool-aid of white supremacy” but became a devout follower of ISIS as a teenager was arrested last week a day before he planned to attack a local church with guns and a notional “flame sword,” the FBI said.

Alexander Scott Mercurio of Coeur d’Alene, Idaho, appeared in court Wednesday on charges of attempting to provide material support and resources to the Islamic State group known as ISIS. Mercurio faces a 20-year sentence if convicted on the federal charges.

In a 47-page affidavit that led to his arrest, an FBI agent who tracked Mercurio laid out how the 18-year-old planned an attack on one or more churches in Coeur d’Alene. In online chats and emails, Mercurio told an FBI informant how, his interest in ISIS grew in his teen years as his parents threatened to force him to attend in-person public school or even “juvenile camp” if he did not cut his beard and wear his pants over his ankles.

The FBI arrested Mercurio on April 6, after he recorded a Ba’yah, an oath often “recited by ISIS affiliates before martyrdom attacks,” according to the FBI. He had planned the attacks for April 7, the FBI said, a date “intentionally selected by him so his attack would occur before the end of Ramadan,” according to the affidavit filed in Idaho federal court. 

The attack plans he detailed to a confidential informant and in chats did not lack violent imagery. But Mercurio admits he had no intention to rehearse or train for the attacks, according to the FBI and his communications with the FBI informant show little understanding of weapons beyond fanciful advice found via Google and online videos.

A bloody plan but no rehearsal or training

Mercurio told the informant that he planned to go to the church on foot due to the fact that he only had a learner’s permit rather than a driver’s license “which requires an adult to ride with him,” according to court documents.

He discussed stealing his father’s guns for use in the attack — either by killing his father or handcuffing him — but as the attack drew closer, according to the affidavit, Mercurio appeared to settle on plans for a melee-style assault using a pipe — which he called a ‘baton — along with a machete, knives and butane. 

At a hotel in the days before the attack, Mercurio laid out a plan to enter a church and strike churchgoers “in the elbows and knees” with the pipe, which he bought at a hardware store. He would then “slit their throats.” The FBI found a machete and a 4-inch knife at Mercurio’s home when he was arrested.

“My plan is pretty solid right now: walk into a church and then start beating people with a baton,” he wrote in a chat to the informant. “Hit them first on thr [sic] kneecaps and elbows. Batons aren’t meant for mass crowd attacks. I have to be slow and methodical. I will beat them only to incapacitate them, I will use my knives and machete to slit their throats and kill them.”

Mecurio also said that, to start fires, rather than kerosene, he purchased hand sanitizer as a “substitute,” which he appeared to equate with highly-flammable materials like oil-based tar. “Sanitizer isn’t explosive but its flammable,” he wrote to an FBI informant. “It burns a long time because it is vicious [sic], kind of like tar. Safer than tar too, no dangerous toxins released into the air.”

Mercurio had purchased two butane bottles and hand sanitizer for the attack, telling the FBI informant that the hand butane bottles would serve as a crude bomb. Once the churchgoers were “dead or gone,” Mercurio said, he would start fires using the hand sanitizer —  and “chuck the gas cans at the fires” to cause explosions.

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Mercurio also told the CI he hoped to cover part of the pipe with electric tape and set it on fire. turning it into what he called a “flaming sword.” Striking victims with the flaming sword, he said – though he admitted in a chat it was ‘not really’ a sword — would hopefully cause infections in victims.

Material Support of ISIS

On Wednesday, prosecutors filed a motion for Mercruio’s detention until a trial, citing the evidence against him and his potential danger to the local Idaho community. 

The FBI’s Joint Terrorism Task Force’s investigation began after Mercurio reached out to “confidential human sources online” indicating his support for ISIS and terror organizations “more generally,” according to the federal affidavit. Mercurio allegedly spread ISIS propaganda online and discussed traveling from the U.S. to join the terror group which is active in parts of Syria and Iraq.

An email to Mercurio’s lawyer and requesting comment was not returned. A spokesperson for the public defenders’ office declined to comment.

During the FBI investigation, officials tracked an in person meeting between Mercurio and a “confidential human source.” Mercurio allegedly told them that “he had previously ‘drank the Kool-aid’ of white supremacy, but after finding Dawlah, [the Islamic State] Mercurio felt there was more purpose for him.” 

Mercurio explained that his deen, or religious path, was from Dawlah, which he uses interchangeably with ISIS (according to the FBI) and that it started during the pandemic while schools were closed. He was introduced to ISIS from a source he met online from Canada, the affidavit said.

“This case should be an eye-opener to the dangers of self-radicalization, which is a real threat to our communities,” FBI Special Agent Shohini Sinha said in the DOJ release.

The case comes a couple weeks after an ISIS-affiliate claimed responsibility for a terror attack in Moscow, Russia at the end of March. Following the attack, Pentagon officials noted the group’s continuous threat and growth to other areas of the world like Central Asia and Africa.

Counter-ISIS missions by the U.S. and partner forces continued over the last few months with 66 missions in Iraq and 28 in Syria – resulting in 18 ISIS operatives killed and 63 more detained, according to U.S. Central Command. Officials said that approximately 2,500 ISIS fighters remain in the two countries, despite the fall of the group’s last refuge in Baghouz, Syria in 2019.  

FBI investigation 

In 2021, the FBI came across Mercurio during an investigation into crypto exchanges and other financial service platforms used in money laundering schemes for terrorist organizations in Syria like ISIS and ISIS-K. FBI officials came across three individuals who collected and provided funds and other financial support to ISIS, including one residing in Gaza.

Mercurio also told the FBI informant that he wanted to give him all of the money in his wallet for whatever he wanted. Mercurio “left $56 and some change on the table” despite the informant’s refusal to take the money, according to court documents.

Investigators eventually linked Mercurio to a username from a mobile messaging app where certain facts corroborated his identity including his age at the time and his parents’ ethnic background. In his messages, Mercurio allegedly shared his parents’ concerns over his conversion to Islam.

“I gotta keep my Imam firm, no matter what. They may even send me to a ‘youth program’ (ship me off hundreds of miles to force me to ‘behave’) etc etc. Kinda scared but In Sha Allah everything will be okay,” Mercurio said.

During an in-person meeting with another suspect, Mercurio allegedly told them that his parents were not happy about his deen – a term meaning “the path” is Islamic terminology – and had it hide it from them.

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