Army Sgt. 1st Class Ikaika Erik Kang, who faces 25 years in prison for attempting to aid the Islamic State group and its campaign of terror, had planned a mass shooting in downtown Honolulu and in Waikiki just after last year’s Fourth of July, the U.S. Attorney for the District of Hawaii said Wednesday following Kang’s guilty plea in federal court.

After pledging allegiance to Islamic State, also known as ISIS, and its leader and kissing the group’s flag in a ceremony at Kang’s Oahu home on July 8, 2017, the active-duty soldier “expressed a desire to commit a shooting downtown and in Waikiki later that same day,” U.S. Attorney Kenji Price said. “The same day Kang was arrested by federal agents. … The community is a safer place today.”

Kang, now 35, had an AR-15 assault-style rifle and an unspecified pistol in his home off base from his post at Wheeler Army Airfield. Born and raised in Waimanalo, Kang graduated from Kaiser High School in 2001.

Price declined to offer details on Kang’s plan for the shootings.

But the U.S. Department of Justice in a subsequent statement said, “On July 8, 2017, Kang swore an oath of loyalty, known as ‘bayat,’ to ISIS and its leader, Abu Bakr al-Baghdadi, in a ceremony conducted by the purported ISIS sheikh. After the ceremony, Kang kissed the ISIS flag. Kang then said that he wanted to get his rifle and go and fight; just go to downtown Honolulu and Waikiki strip and start shooting.”

In exchange for Kang’s guilty plea, prosecutors said they won’t charge him with additional crimes, including violations of the Espionage Act, other terrorism-related laws and federal firearms statutes.

Kang is the only person in Hawaii to be “convicted of attempting to provide material support to a designated foreign terrorist organization,” Sean Kaul, special agent in charge of the FBI’s Honolulu field office, said in a statement.

But Wednesday’s revelation of his plans for homegrown terror on Oahu added a frightening detail to previous disclosures that Kang was helping IS efforts abroad.

The Army alerted the FBI about Kang in August 2016, after he had watched violent Islamic State videos online and made statements in support of IS, Price said.

The FBI put Kang under surveillance and the investigation grew to include the Army’s Criminal Investigative Division and the Joint Terrorism Task Force in Honolulu.

By late June and July of 2017, Assistant U.S. Attorney Kenneth Sorenson said in U.S. District Court Wednesday, Kang had several meetings at his home with undercover FBI agents whom Kang believed had IS connections — including later meetings involving an FBI agent who was portrayed as a high-ranking IS leader, or “sheikh,” and another who claimed to be an IS fighter.

In a statement Wednesday, the U.S. Department of Justice said Kang gave the undercover FBI agents “sensitive, non-public military documents, some of which were classified at the SECRET level.”

The documents, according to the Justice Department statement, included “classified air traffic control documents that describe call signs, aircraft types, route points, directives, mission procedures, and radio frequencies; the U.S. military’s ‘weapons file,’ which describes all the armament capabilities of the U.S. armed forces; details about a sensitive mobile airspace management system used by the U.S. military; and documents containing personally identifiable information of U.S. service members.”

Kang, trained as an air traffic controller with a secret security clearance, also provided the FBI agents with a commercial aerial drone and a military tactical vest, and described how IS could use the drone to track U.S. troop movements and evade American armored vehicles, Sorenson said in court.

After meeting with the purported IS fighter, Sorenson said Kang, also a trained Army combat instructor, appeared in what Kang thought was an IS training video demonstrating hand-to-hand tactics and how to use Kang’s weapons.

Kang was obsessed with videos depicting terrorism beheadings, suicide bombings and other violence, and he watched them in his bedroom for hours daily, a confidential informant told agents.

Kang told the informant that if he became an Islamic State member, he would become a suicide bomber and attack Schofield Barracks, according to an affidavit filed in the case.

Kang watched the videos for four to five hours each weekday 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,” the affidavit 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.”

Kang began researching Islam 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. He served two tours in the Middle East — the first in Iraq and the second in Afghanistan.

The U.S. government asked a judge to allow a tracking device to be placed on Kang’s car in October 2016 and received several extensions. 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.

After pleading guilty to four counts in federal court on Wednesday, Kang’s sentence of 25 years in prison was scheduled to be reviewed on Dec. 10 by senior U.S. District Judge Susan Oki Mollway.

“In federal court, a 25-year sentence is a 25-year sentence,” said Kang’s court-appointed attorney, Birney B. Bervar.

If he had not pleaded guilty, Kang faced the possibility of life in prison and a $250,000 fine, which Bervar said Kang could not possibly pay.

“He’s accepting responsibility,” Bervar told reporters outside U.S. District Court following Kang’s plea. “… He may have more to say at sentencing.”

Kang Wednesday morning stood before Magistrate Judge Kenneth J. Mansfield in a white, short-sleeved jumpsuit that revealed heavy tattoos on both arms. His dark hair was trimmed close, his feet were shackled, and his hands chained around his waist.

Mansfield rejected a request by Bervar that Kang’s hands be unchained for his court appearance. Instead, Kang held up his right hand to waist level as he was sworn in for the proceeding, which required him to answer at several points that he understood the charges against him and the ramifications of pleading guilty.

Kang admitted in court that he provided classified information and the drone, and that he was in the supposed IS combat training video.

After the hearing, he was taken back into custody. If Mollway accepts the terms of Kang’s plea agreement, it will be up to the Federal Bureau of Prisons to determine where he serves his sentence.

Kang is still in the Army, but his duty status is confined, said Lt. Col. Curt Kellogg, with the 25th Infantry Division. Because Kang is in civilian confinement, the Army isn’t paying him, Kellogg said.

The Associated Press contributed to this report.