COEUR d’ALENE — The 18-year-old Coeur d’Alene resident accused of planning to attack local churches with a machete, fire and guns on behalf of ISIS is expected to make his first appearance in federal court today.

Alexander S. Mercurio is charged by federal complaint with attempting to provide material support or resources to a designated foreign terrorist organization.

Authorities arrested Mercurio on Saturday, the day before federal prosecutors believe he planned to attack people attending a church near his home in Coeur d’Alene. He allegedly planned to incapacitate people by beating them with a metal pipe, “slit their throats with a knife or a machete” and then start fires inside the church.

Mercurio graduated from Lake City High School in 2023. He attended North Idaho College and was on the dean’s list in fall 2023.

Court records indicate he adopted the Islamic faith against the wishes of his parents, who divorced in 2019. He told informants that his parents had threatened to send him to “in-person school” to keep him from praying or to a “youth camp or juvenile hall or something.”

“Mercurio told (a source) that his family ‘oppresses’ him and that both of his parents do not like that he is Muslim,” court records said. “Mercurio advised that his parents don’t give him a hard time about it due to the fact that he is keeping out of trouble, getting good grades, working and keeping his worship to himself.”

The FBI began monitoring Mercurio’s online activity as early as 2022, while conducting a criminal investigation into a fundraising network that uses cryptocurrency exchanges and other platforms to raise funds and launder money for foreign terrorist organizations.

Mercurio communicated with ISIS supporters online, some of whom were really “confidential human sources” who reported information about Mercurio’s plans to federal investigators. The plans grew increasingly detailed leading up to April 6, the day of his arrest.

Mercurio told a source he previously “drank the Kool-aid of white supremacy,” according to court documents, but felt ISIS had more purpose for him.

On Mercurio’s school-issued laptop, investigators found numerous audio files of songs and chants that “glorified the Islamic State and celebrated the conquests of the Islamic State,” as well as files “confirming Mercurio’s commitment to ISIS and its ideology.”

Mercurio allegedly told sources he planned to “carry out a martyrdom operation” in Coeur d’Alene on April 7, according to court records. Just before doing so, he said he wanted to donate “every last cent” in his bank to ISIS, a sum of around $11,000.

The Kootenai County Task Force on Human Relations weighed in Tuesday on Mercurio’s arrest and alleged plans. The task force was formed in 1981 with the mission of countering area hate groups, including the Aryan Nations.

“Let’s not forget that no community is exempt from the threat of violence by one or more groups or individuals,” the task force said in a news release Tuesday. “We need to support law enforcement and prosecutors, along with proper laws to keep our communities safe. Constant awareness is essential for the safety of our citizens. We must never let down our guard that can result in great tragedies.”

If convicted, Mercurio faces a maximum of 20 years in federal prison.

    Alexander S. Mercurio, 18, of Coeur d'Alene, poses in front of an Islamic State flag gifted to him by an FBI informant.