"Why would he do that?" US soldier arrested after pledging loyalty to Islamic State

HONOLULU  — A U.S. soldier who was recently arrested on terrorism charges expressed support for the Islamic State group as early as 2011, but remained in the Army for years while the military and the FBI investigated to determine whether he posed a threat, authorities said.

Sgt. 1st Class Ikaika Kang was taken into custody over the weekend after the 34-year-old veteran of deployments to Iraq and Afghanistan declared his loyalty to the terrorist group and exclaimed that he wanted to "kill a bunch of people," according to authorities.

The case highlights the challenges investigators face with protecting the public from a potentially dangerous actor on one hand and gathering sufficient evidence to enable prosecution on the other.

Kang is on record making pro-Islamic State comments and threatening to hurt or kill other service members back in 2011, according to an FBI affidavit filed Monday in federal court.

The Army revoked his security clearance in 2012, but gave it back to him the following year. Last year, the Army called the FBI when it "appeared that Kang was becoming radicalized," the affidavit said.

Retired Army judge and prosecutor Col. Gregory A. Gross said he was perplexed that the Army allowed Kang to remain a soldier even after his favorable comments toward the Islamic State group.

But Gross said the Army may have decided Kang was just mouthing off and was not a threat.

Gross served as the initial judge in the court martial of Maj. Nidal Malik Hasan, an Army psychiatrist who killed 13 people and wounded more than 30 in a 2009 shooting at Fort Hood, Texas. He said Tuesday he was concerned by the similarities between Kang and Hasan's case.

Kang's court-appointed defense attorney, Birney Bervar, said his client may suffer from service-related mental health issues of which the government was aware but neglected to treat. He declined to elaborate.

The FBI believed Kang was a lone actor and not affiliated with anyone else, said Paul Delacourt, the FBI agent in charge of the Hawaii bureau.

A 26-page affidavit from FBI agent Jimmy Chen filed Monday in court detailed how Kang thought he was dealing with people working for Islamic State but who were actually undercover agents.

Kang and the agents together made combat training videos he believed would be taken to the Middle East to help prepare the group's soldiers to fight American forces, according to the affidavit. Kang had received the highest level of combat training available in the Army and was a mixed martial arts enthusiast.

Also on Saturday, Kang and an undercover agent allegedly went shopping for a drone to give to Islamic State fighters.

A trained air traffic controller based at Hawaii's Wheeler Army Airfield, Kang had his military clearance revoked in 2012 for making pro-Islamic State comments while at work and on-post and threatening to hurt or kill fellow service members.

His clearance was reinstated a year later after he completed military requirements.

Kang's father told Honolulu television station KHON and the Star-Advertiser newspaper his son may have had post-traumatic stress disorder. Kang told the newspaper he became concerned after his son's return from Afghanistan. He said his son was withdrawn.

Kang has two firearms registered in his name, an AR-15-style rifle and a handgun. After the shooting last summer at a gay nightclub in Orlando, Florida, he told a confidential source that the shooter "did what he had to do" and later said that America is the only terrorist organization in the world, according to the affidavit.

The document alleges he also later told the same source that "Hitler was right" and that he believed in the mass killing of Jews.

He told the source he was angry at a civilian who had taken away his air traffic controller's license and that he wanted to torture him, the affidavit said.

"Kang said that if he ever saw him again, he would tie him down and pour Drano in his eyes," the affidavit said.

He enlisted in the Army in December 2001, just months after the Sept. 11 attacks. He served in South Korea from 2002 to 2003. He deployed to Iraq from March 2010 to February 2011 and Afghanistan from July 2013 to April 2014.

Kang was scheduled to appear in court Thursday for a detention hearing.

Red tape with the word "evidence" on it covered part of the door to the Kang's apartment in the Honolulu suburb of Waipahu.

Dee Asuncion, a real estate agent who represented Kang when he bought his home less than a year ago, said he came across as a "very respectful guy." She said he was "on the shy, quiet side."

But looking back, she said, there was one conversation that seemed strange to her. He talked about having respect for the ideology of Islamic terrorist groups.

"It sounded like he was just curious," she said, adding that in the same conversation he talked about helping his dad renovate his home.

"I feel bad for him that he went down that road," Asuncion said.