BOISE, Idaho (AP) — An Idaho teenager is charged with attempting to providing material support to the terrorist group ISIS after prosecutors said he planned to carry out an attack on a Coeur d’Alene church.

Alexander Scott Mercurio, 18, was arrested Saturday, and the charges were unsealed in in Idaho’s U.S. District Court on Monday. Court documents do not reveal if he has hired an attorney, and a phone number for his family could not be immediately located. Mercurio did not immediately respond to an email sent to him through a jail inmate email system.

In a sworn statement filed in the court case, FBI task force officer John Taylor II said Mercurio talked with confidential informants over a two-year span, eventually detailing a plan to attack churchgoers near his northern Idaho home on April 7 using a variety of weapons including a metal pipe, a knife and fire. Taylor said that Mercurio planned to continue the attacks at other churches until he was killed, and he tried to build an explosive vest to wear during the attacks.

The attacks never occurred. Law enforcement arrested Mercurio on April 6.

Mercurio told a confidential informant that he first connected with ISIS during the start of the COVID pandemic, when schools were closed, Taylor said, and investigators later found several files on his school-issued laptop detailing ISIS ideology. Mercurio’s parents disapproved of his beliefs, he allegedly told a confidential informant posing as an ISIS supporter, and Mercurio eventually began to worry that he was a hypocrite for not yet carrying out an attack, Taylor wrote.

“I’ve stopped asking and praying for martyrdom because I don’t feel like I want to fight and die for the sake of Allah, I just want to die and have all my problems go away,” he reportedly wrote in a message to the informant, according to the complaint.

On March 21, Mercurio sent a direct message to the informant again, saying he was restless, frustrated and wondered how long he could keep living “in such a humiliated and shameful state,” Taylor said.

“I have motivation for nothing but fighting ... like some time of insatiable bloodlust for the life juice of these idolators; a craving for mayhem and murder to terrorize those around me. I need some better weapons than knives,” the direct message said, according to Taylor.

Law enforcement moved to arrest Mercurio after he sent an audio file pledging his allegiance to ISIS, Taylor said.

“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,” Attorney General Merrick Garland wrote in a press release. “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.”

If convicted, Mercurio could be sentenced to up to 20 years in prison. Mercurio has not yet had an opportunity to enter a plea, and he is being held in a northern Idaho jail while he awaits his first court appearance.