(CNN)On July 28, 2016, FBI Special Agent John Sikorski received an encrypted message with a list of Google Play gift card codes. The total value of the gift cards was $245. Despite the modest sum, it was a big win many years in the making for the FBI's counterterrorism unit.
How a Nazi-sympathizing cop went to jail for aiding ISIS
Sikorski was working undercover, posing as an American named Mo who had joined ISIS in Syria. He had sent a message to terror suspect Nicholas Young, requesting gift cards to help fighters communicate with recruits via an encrypted app.
After Young sent the Google Play codes, he was arrested and charged with providing material support to a foreign terrorist organization.
It took six years and millions of dollars to prosecute Young, according to a court filing. Young, 38, was a Virginia-based Metro DC transit officer who converted to Islam after the death of his father sent him spiraling into depression.
Agents participating in the case gave Young the code name Slow Decline.
Even as the FBI was investigating Young as a possible terrorist sympathizer, he continued to work as a transit cop, carrying a service weapon and patrolling train stations around the nation's capital. During a jailhouse interview with The Washington Post, Young acknowledged he enjoyed violent movies, death metal and dark humor but he stressed he did not support the Islamic State.
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"They're really grasping at straws here, trying to take everything I said out of context and take it in the most sinister light," Young said. (When contacted by CNN, Young's attorney said his client is not interested in participating in any further interviews).
Young's sister told the newspaper, "The only thing extreme about my brother is his videogame playing."
The Slow Decline sting operation involved at least two undercover employees and a paid informant who called himself Mo, who bonded with Young by discussing ex-girlfriends and misadventures on the dating scene. The informant and his handling agent made a taxpayer-funded trip to Turkey so they could take photos of landmarks to make Mo's story of joining ISIS abroad more believable.
The FBI had reasons for investing time and resources in Slow Decline. The investigation began in 2010, after one of Young's college acquaintances, Zachary Chesser, was arrested for attempting to provide material support to Al-Shabaab. At the time, Young told the FBI he was shocked. He said it would have been his personal and religious duty to report any suspicious activity.
Meanwhile, Young was engaged in a dispute with his supervisors at Metro DC, who were concerned about the length of his beard and his display of religious items, including a Quran, in his workspace. It is unclear whether Young's bosses reported him to the bureau.
An undercover FBI employee, "Khalil" met Young at a wedding while looking into suspected jihadists in the Washington suburbs. Khalil described himself to Young as a disillusioned Marine who felt the military would revoke his security clearance if they learned he practiced Islam. During their first conversation, Young talked about conspiracies against Muslims in America, according to trial transcripts.
Khalil began keeping notes on Young even though his main job was investigating one of Chesser's associates, Liban Mohamed, a former taxi driver who ultimately traveled to Somalia and joined Al-Shabaab. Mohamed was apprehended overseas in 2015. Young had no links to Mohamed beyond the fact that they both knew Chesser.
For more than a year, Young confided in Khalil, praising Ron Paul and criticizing Barack Obama as they met up for meals, movies and walks on golf courses. He told Khalil he got word from a female friend that he was under investigation. Young said he feared his phones were tapped and his home was being surveilled. He boasted about his gun collection and said he had a right to shoot anyone who trespassed on his property. If law enforcement tried to search his house: "That's what amphetamines, ballistic vests and assault rifles are for."
Khalil also reported that Young had joked about kidnapping, sexually assaulting and torturing a female FBI agent who interviewed him, according to prosecutors.
It was a pattern that continued for years, documented in court records. Young's comments would raise red flags, yet he didn't cross the threshold into illegal conduct. His record was clean aside from one traffic infraction.
Twice in 2011, Young vanished for weeks without explanation, Khalil testified. He used vacation time to make two trips to Libya during the Arab Spring uprising against Moammar Gadhafi. While abroad, he connected with members of a rebel group called the Abu Salim Martyrs Brigade, according to encrypted messages presented as trial exhibits.
Based in the port city of Derna, the brigade had alleged ties to al Qaeda and advocated for Sharia law. In 2015, roughly a year after the Islamic State declared its caliphate, the brigade fought back against ISIS' attempt to take over Derna.
When Young returned from his first visit to Libya, he told authorities at the airport that he had provided medical aid to injured rebels at various locations in Misrata and Benghazi (where the Abu Salim Martyrs Brigade had little to no presence). He said he had handled an AK-47 while riding in a Jeep but did not fire the weapon. Young talked about ducking gunshots and mortar rounds in Misrata while wearing a ballistic vest with a red crescent painted on the back. He was later diagnosed with PTSD by a court-appointed psychologist.
Young didn't mention Derna or the Abu Salim Martyrs Brigade while being questioned by an airport investigator from the Department of Homeland Security, nor would he identify the individuals he had met in Libya. At the end of the interview with DHS, he said, "What gives? I've been getting the stink eye since 2008."
Customs and Border Protection agents confiscated body armor that had been found in his luggage. Although the Transportation Security Administration generally allows individuals to travel with body armor in carry-on and checked bags, security officers may seize items for evaluation.
Young participated in World War II re-enactments, portraying a Nazi storm trooper named Klaus Düsselkamp. He legally owned approximately 19 guns, as well as tactical gear and about 60 knives, daggers and swords. He had 18,000 rounds of ammunition. The back of his truck was emblazoned with bumper stickers: "Boycott the terrorist state of Israel" and "Libyan Civil War Vet, Siege of Misrata, April-May 2011."
In an era of active shooters and fringe political violence, the FBI has a mandate to stop potentially dangerous individuals before they act. Investigating suspected homegrown violent extremists -- people inspired by the global jihadist movement -- remains its top priority, but law enforcement is also concerned about domestic terrorism, FBI director Christopher Wray said during an August speech at a national secur