A Hawaii-based Army soldier was obsessed with videos depicting terrorism beheadings, suicide bombings and other violence and he watched them in his bedroom for hours every day, a confidential informant told agents who put a tracking device on the soldier's car during an investigation that led to an indictment charging him with attempting to support the Islamic State (ISIS) group.

An affidavit supporting the tracking device request and other newly unsealed court documents provide more details about Sgt. 1st Class Ikaika Kang's alleged fixation with ISIS violence.

Kang told the informant if he became an ISIS member, he would be a suicide bomber and attack Schofield Barracks, a sprawling Army base outside Honolulu, the affidavit said.

The documents were unsealed Monday.

Kang has pleaded not guilty and is being detained without bail.

The indictment and an FBI affidavit filed previously alleged that Kang met with undercover agents he believed were part of ISIS. He allegedly provided them with classified military information, a drone, military equipment and training in combat fighting.

His defense attorney, Birney Bervar, said Tuesday he hadn't yet seen the unsealed documents. He said previously Kang may suffer from service-related mental health issues that the government was aware of but neglected to treat.

The U.S. government first asked a judge to allow a tracking device on Kang's Lexus sedan in October 2016 and applied for several extensions after orders granting it expired.

Kang watched the violent videos for four to five hours each day during the week and more on the weekends, the informant told agents in 2016. The informant "remembered feeling sick to his stomach, while Kang laughed and insulted the victims," an affidavit filed under seal in May 2017 said.

During the first week of September 2016, Kang told the informant "that if he were to do something like shoot up a large gathering, it would be out of his hatred for white people, the wicked and non-Muslims," the affidavit said.

Kang began researching the Muslim religion in 2014, couldn't wait to move to the Middle East to "join the cause" and was "only in the military for a paycheck," the informant said, according to the affidavit.

Agents said in their applications for a tracking device that they needed to monitor him continuously because they feared he would carry out an attack.

Officials with the 25th Combat Aviation Brigade told the FBI they were concerned over their ability to monitor Kang, noting that he was to return from leave on May 25, 2017 — the same day as a change-of-command ceremony, the affidavit said. Brigade personnel feared the large gathering "represented a target of opportunity for Kang should he want to harm members of the unit."

Kang was arrested in July. Trial is scheduled for later this year.