The FBI arrested an Idaho man Saturday who had allegedly made plans to attack a church in the state and was attempting to provide material support and resources to ISIS.

Alexander Scott Mercurio, an 18-year-old from Coeur d’Alene, is currently in custody awaiting a court appearance. He is charged with attempting to provide material support or resources to a designated foreign terrorist organization and faces a maximum penalty of 20 years in federal prison if convicted.

It’s alleged Mercurio planned to carry out a suicide attack on churches in Coeur d’Alene including one the affidavit claims he identified. “Mercurio made the statement that there were too many churches, and ‘I am going to fix that real soon,’” the affidavit stated.

The FBI’s Joint Terrorism Task Force conducted an investigation and worked with a confidential human source before Mercurio’s arrest, according to the affidavit. Allegedly, Mercurio planned to attack a church on April 7, 2024 and had a plan to incapacitate his father and steal firearms from him to carry out the attack.

Mercurio allegedly pledged his allegiance to ISIS, “stating his intention to die while killing others on behalf of ISIS.”

The investigation started when Mercurio reached out to confidential human sources online and allegedly indicated his support for ISIS and terrorist organizations.

Before allegedly planning his attack on an Idaho church, the FBI obtained copies of electronic files from Mercurio’s school-issued laptop. The files include a Jihad chant and “numerous files confirming Mercurio’s commitment to ISIS and its ideology.”

The affidavit claims that “beginning in October 2022 through the time of this arrest, Mercurio has continued to express his intent to fight for ISIS through declaring his Ba’yah, or oath, to ISIS and developing his plans and actions on how he might support the ISIS cause.”

In addition to investigating Mercurio’s alleged online activities, a source made contact with Mercurio.

A confidential human source picked up Mercurio from a Coeur d’Alene park in February 2024, the affidavit claims that Mercurio told the source that his parents did not approve of his religion. After the two made contact at the park, the affidavit said they communicated via a messaging system.

According to the affidavit, the FBI Online Covert Employee with whom Mercurio talked to received a message on or about March 26, 2024 from Mercurio that allegedly said, “I wanted to tell you something important. I am going to perform a martyrdom operation very soon (by the will of Allah). It will occur in the last few days of Ramadan. The targets will be the various churches in my town.”

The affidavit claims Mercurio met with a confidential human source on or about April 2, 2024 and allegedly disclosed that he would walk to a church near his home and kill people with his knife and/or machete. He also allegedly stated he planned to donate his savings to ISIS.

The next day, Mercurio allegedly repeated the plan of attack to the source “but included that he will try to hijack a car to get to the next church.”

Days later on Saturday, law enforcement executed a search warrant at his home. The affidavit claims that they found “items consistent with his planned attack (butane canisters, lighters, a pair of handcuffs, a knife, a pipe, and a machete)” as well as an ISIS flag. Mercurio was then arrested.

“As alleged in the complaint, the defendant swore an oath of loyalty to ISIS and planned to wage an attack in its name on churches in Coeur d’Alene, Idaho,” said Attorney General Merrick B. Garland in a Justice Department release. “Thanks to the investigative efforts of the FBI, the defendant was taken into custody before he could act, and he is now charged with attempting to support ISIS’s mission of terror and violence. The Justice Department will continue to relentlessly pursue, disrupt, and hold accountable those who would commit acts of terrorism against the people and interests of the United States.”

FBI Director Christopher Wray said, “The defendant allegedly pledged loyalty to ISIS and sought to attack people attending churches in Idaho, a truly horrific plan which was detected and thwarted by the FBI’s Joint Terrorism Task Force. This investigation demonstrates the FBI’s steadfast commitment to work with our law enforcement partners to stop those who wish to commit acts of violence on behalf of – or inspired by – foreign terrorist groups.”