Mohammed Hamzah Khan knew he was being watched. The 19-year-old college student passed through security at O’Hare with his 17-year-old sister and 16-year-old brother on the afternoon of October 4, 2014. But even then, he expected to be stopped by federal agents who he thought had been spying on him. He was right.

Khan, the oldest child of Indian immigrants, had grown up in suburban Bolingbrook. Average height, with short dark hair and a beard that was still growing in, he would not stand out in a busy international airport. However, as he and his siblings headed toward the gate for Austrian Airlines flights to Vienna and then Istanbul, two U.S. Customs and Border Protection officers approached.

The officers later claimed they interviewed the teenagers as part of “routine outbound inspection procedures.” Yet it was soon clear that federal authorities already knew a lot about Khan.

The customs officers separated the siblings. As an FBI agent looked on, the officers asked Khan why he was traveling to Turkey and what he planned to do there. He initially said he and his siblings wanted to see some sights, such as the Blue Mosque and Topkapi Palace, and planned to stay in a hotel.

But Khan’s siblings told different stories, according to the federal officers: his sister said they intended to stay with a friend, while his brother said they were going to visit their cousins.

The officers then asked Khan if he would be willing to talk with FBI agents at a secure facility in another part of the airport. Khan was not formally under arrest, and the officers and agents later stressed that they told him the conversation was “voluntary,” though they would have to handcuff him for the car ride over. “Khan stated he was willing to talk to the FBI,” the agents later wrote in a report.

Once they arrived at the FBI facility, the handcuffs were removed and three agents led Khan into an interview room. They asked Khan to confirm that he used three different e-mail addresses, the Twitter handle @lionofthed3s3rt, a Facebook page in his name, a cell phone number in the 847 area code, and an account with KIK, an instant messaging app. After Khan said the accounts were all his, the agents began to go over some of his communications, which they had been reading for months.

Over the course of the two and a half hour interview, Khan “admitted” what they already knew: he had been exchanging messages with a person who went by the name Abu Qaqa and was a recruiter for the Islamic State of Iraq and Syria. Khan and his siblings weren’t headed to Turkey on vacation—they had been attempting to reach Syria so they too could live in what ISIS has declared to be an Islamic caliphate.

The agents didn’t accuse Khan or his siblings of plotting against the United States or contemplating any specific violent acts. But under federal law, if they were en route to ISIS territory, that meant they were attempting to provide “material support” to a foreign terrorist organization, a crime punishable by up to 15 years in prison.

Early the next morning—after Khan was questioned for nearly 12 hours without an attorney present—federal officials formally charged him, though they elected to release his underage siblings to their parents. Within hours the case generated international news coverage that wondered how a polite suburban teenager with college-educated parents could have been lured to a brutal terrorist group.

Yet as it unfolds in federal court in Chicago, Khan’s case also highlights questions about the government’s approach to counter- terrorism investigations. In a string of busts in the Chicago area in recent years, federal agents and informants spent months secretly monitoring and sometimes even encouraging young Muslims drawn to extremist groups. Though many of these individuals show signs of mental or emotional instability, authorities intervened only when they were ready to hit them with terrorism charges.

Attorneys for the accused and other critics say the pattern raises questions about whether the government’s practices are just—and also whether they’re the best way to keep the public safe. They argue that Khan’s case offers an opportunity for a more fair and productive approach.

“We’re not saying, ‘Don’t investigate threats,’ ” says Andrea Prasow, the deputy Washington director for Human Rights Watch, one of the authors of a 2014 report on federal terrorism cases, and former defense counsel for a group of Guantanamo detainees. Prasow says the Justice Department often employs informants who come close to practicing entrapment, and it shows little discernment in the cases it brings under broad antiterrorism laws. “You can be the guy who posts all this pro-ISIS stuff from your parents’ basement and then goes off to high school, or you can be someone who’s planning a bomb attack.”

The U.S. government sees no room for error when ISIS has posted videos of beheadings, jihadist sympathizers from the Middle East to the United States have carried out attacks, and American citizens want assurance that domestic threats are being thwarted. “The problem is that we get so few shots at terrorists that when we catch one it’s like Moby Dick,” says Thomas Mockaitis, a professor of history at DePaul and an analyst on terrorism and insurgencies.

While it’s critical to stop potential extremists before they’re drawn to carrying out violence, Mockaitis is in a camp calling to respond where possible with “restorative justice” such as education and counseling—much the way that former cult members are often led through a “deprogramming” process. “We did the right thing to arrest him,” he says of Khan. “The question is what we do now.”

Outside of formal charges and court proceedings, law enforcement officials won’t discuss their counter-terrorism strategies. “I can assure you the threats are real,” one Chicago-based official told me, but wouldn’t say more. A spokeswoman for the FBI also declined to comment, even generally or on background.

Since ISIS captured swaths of Iraq and Syria last year, its brutality has been well documented. Beyond the well- covered executions of Westerners, thousands of Muslims have been slaughtered for not following the group’s medieval interpretation of Islamic law. And several avowed followers have carried out violent attacks in Europe and the United States, including a May shooting at an event organized by an anti-Muslim group in Texas.

Yet ISIS continues to attract followers and would-be followers drawn to its claim of creating a caliphate, a purported holy kingdom led by successors of the prophet Mohammed. In the eyes of those who accept the declaration, living in the caliphate is both an obligation and an opportunity for salvation, as sympathizers explain in “What ISIS Really Wants,” a February story in the Atlantic detailing its ideology.

Most Muslims don’t share that view of the caliphate, let alone the claim that ISIS has established it. Last September more than 100 Muslim scholars from around the world signed an open letter refuting ISIS’s theological and legal assertions in detail.

Still, the idea of the caliphate appeals to some discontented young men and women, and ISIS has made outreach a priority. “It’s something that started with al-Qaeda, and ISIS has upped the game and has become very good at online propaganda, social media campaigns, and recruitment,” says Ted Reynolds, a senior research fellow in terrorism studies at the University of Central Florida. When someone expresses interest in heading to ISIS territory, “ISIS facilitators then become their travel agents.”

The recruiter known as Abu Qaqa, who allegedly communicated with Khan, has claimed to be a former drug dealer from Britain; for a time he was tweeting rap-style rhymes about the importance of joining the Islamic State.

According to a recent report from the U.S. State Department, more than 16,000 people from more than 90 different countries had traveled to the Middle East to join ISIS by the end of 2014. Authorities estimate about 100 came from the United States.

“You have to understand that for young people here, all their lives we’ve been at war with Muslims,” says Omer Mozaffar, the Muslim chaplain at Loyola University. Mozaffar teaches at colleges and Islamic organizations around the Chicago area and leads programs on countering extremism.

Most teenagers yearn for a group to join, and some immigrant children wonder, “Is this really my home?” he says. In rare instances they can be susceptible to ISIS’s claims that it’s fighting “the big global monster. It becomes a fascination.”

At the same time, extremists aren’t the only threat perceived by the Muslim community. “I know quite a few situations in which informants have approached people at mosques who are slow and asked them to keep in touch,” Mozaffar says. “I have to say that if you come across someone at the mosque promoting violence, they probably work for the feds.”

By their own account, the FBI agents at O’Hare saw little immediate threat in Khan. Around 5:45 PM—two hours after Khan’s flight to Turkey had departed—two agents took him back to the international terminal and bought him a Coke and apple pie at McDonald’s. The three sat at a public dining table, with the two agents noting in their report that they took seats along the wall while Khan was “on the open side of the table.”

A third agent joined them a few minutes later, and they chatted about sports, religion, and dating, the agents said. Khan told them he’d had several girlfriends in high school, including a two-year relationship, and that he’d once met and taken a selfie with Kim Kardashian. Khan said he was taking a semester off from his studies at Benedictine University as he considered switching his major from engineering to computer science. He’d been working at a Menards near his home.

Khan also told the agents he wasn’t surprised he had been detained. “Khan spoke of how he suspected he might be under surveillance by the government,” the agents reported. He’d heard clicking noises on the phone, which made him wonder if it was tapped. He also knew that authorities had monitored and arrested other Muslims who’d tried to travel to Syria.

The conversation at McDonald’s went on for nearly three hours. Around 8:30 PM, one of the agents told Khan that his father was on the way and suggested they walk to the lobby where he’d be arriving. But the FBI had no intention of letting Khan go. As they waited, the agent pulled out his phone and showed him three images that had been taken earlier that day. They were pictures of a handwritten letter Khan had left for his parents at home.

Unbeknownst to Khan, while he had been talking with authorities at the airport, other FBI agents had showed up at his family’s Bolingbrook home, shocked his parents by producing a search warrant, and combed through the house looking for evidence. Khan’s parents said they thought Hamzah was at work and his siblings were sleeping—they’d even stuffed comforters under their sheets to make it look like they were still in bed.

Agents found “multiple handwritten documents . . . which expressed support for ISIL,” prosecutors later alleged, using an alternate abbreviation for ISIS. By “documents,” they meant notes and doodles. A notebook found in the living room with Khan’s name on it included a list of steps to take to get to Turkey and Syria, drawings of the ISIS flag, and mentions of the organization written in Arabic; a planner included another drawing of the ISIS flag.

In Khan’s bedroom, they found his three-page handwritten letter. “FIRST and FOREMOST, PLEASE MAKE SURE TO NOT TELL THE AUTHORITIES,” it said. “For if this were to happen it will jeopardize not only the safety of us but our family as well.”

Khan explained that it was his religious duty to travel to the Islamic State, and expressed weariness at living under scrutiny as a Muslim in the United States. “Tell me, if we were truly free, why do we have to live in fear?”

“I extend an invitation, to my family, to join me in the Islamic state,” he wrote. “You may have thought that I was selfish, but I hope now that you understood my motives to take as much of my family to live in the land of Islam.”

The other teens wrote similar letters. To Khan’s mother, Zarine, the language didn’t sound like anything her children would have come up with, she told the Washington Post, and the message was certainly nothing believed by her or her husband, Shafi, an event planner for a local Islamic organization. Authorities acknowledged that the teens might have been repeating propaganda they learned from an online recruiter.

“We tried to be the best parents we could,” Zarine Khan told the Post. “And they are good kids. This thing came out of the blue. We are still trying to figure it out.”

Back at the airport, Khan confirmed that he’d written the letter and said he understood that “ISIS is a foreign terrorist network,” according to the FBI report. A few minutes later one of the agents asked if Khan would return to the FBI office to clarify some of his statements. He was then interviewed off and on for three and a half more hours. When agents asked him what he planned to do if he reached Syria, he said that “he expected to be involved in some type of public service, a police force, humanitarian work, or a combat role.”

Like many teens who get into trouble, he also worried about what his parents would say. “Khan stated he fears his mother much more than his father, but that both will be very disappointed in his actions,” the agents reported.

Eventually the agents read Khan his Miranda rights, and at almost 2 AM on October 6—nearly 12 hours after he was first questioned by federal authorities—Khan was placed under arrest and transferred to jail.

Khan’s parents hired defense attorney Thomas Durkin, a veteran at handling terrorism cases. Durkin is also known for his mane of hair, thick mustache, and penchant for philosophizing about government overreach.

A November 17 court hearing—to determine if Khan should be locked up while awaiting trial—offered two fundamentally different views of Khan’s offense and the U.S. war on terror. Assistant U.S. attorney Matthew Hiller argued that because Khan had hoped to join one of the most violent terrorist groups in the world, letting him out of jail was too risky. The prosecutor went on to characterize Khan as an enemy of what America stands for.

“On October 4th, the defendant in his own words and actions had rejected Western society, abandoned his parents, abandoned his community, and abandoned his country by trying to travel to Syria to join ISIL,” Hiller said.

Hiller described the notebooks found at the Khan home, pointing out the sketches of the ISIS flag. He said that in May 2014 Khan’s sister, using the handle @deathisvnear, had tweeted heart and smiley-face emoticons after watching a video of ISIS violence. “There are no conditions or combination of conditions that can protect the safety of the community from the defendant,” Hiller said. “At a minimum, [the] defendant and his siblings have been radicalized.”

Durkin shot back that it was the government, and not the Khan teenagers, that was failing to live up to American ideals. “Everybody can concede that ISIS is a bunch of bad dudes,” Durkin said, but the Khan children had truly been convinced it was their religious duty to live in an Islamic caliphate. “What the government is trying to do is use the statements of religious belief as somehow an inference that these people are dangerous and somehow they’re terrorists, which is preposterous.”

Durkin cited Khan’s writings about his religious faith, arguing that he never espoused violence himself. “If they were Irish Catholic and they were going over to fight for the IRA, they’d have been grabbed by their ear by the FBI and pulled in to their parents,” he said “But they didn’t do that to Hamzah Khan.”

He asked that Khan be placed on an electronic tether, put in the custody of an uncle, and provided with counseling until his case was resolved. Incarceration, Durkin argued, will not end the problem of American children being recruited by extremists.

“You know, this is very close to a thought crime,” Durkin said. The Khan teens “don’t like free markets, apparently. You know, but neither do I. It’s a good thing they don’t lock me up.”

After Durkin was done, Judge Cox reminded him that it wasn’t her job to evaluate Islamic theology or American foreign policy—only whether Khan should remain in jail. She stressed that while Khan has a right to his religious beliefs, he had still shown a willingness to abandon his home and join a designated terrorist group. For that reason, she said, he would have to remain locked up.

At the same time, Judge Cox said, “The writings that have been introduced into evidence show me that the defendant is not stable.”

In the months since, Durkin has cited Cox’s comments while fighting for Khan to be provided with education and counseling. The government has questioned what services could protect the community from an ISIS sympathizer. In one court filing, prosecutors underscored their point by including a list of people beheaded by the group overseas.

After a court hearing in January, Khan’s mother read a statement to the press. “The venom spewed by these groups and the violence committed by them find no support in the Quran and are completely at odds with our Islamic faith,” she said. “We condemn the brutal tactics of ISIS and groups like it. And we condemn the brainwashing and recruiting of children through the use of social media and the Internet.”

She added that she had a message directly for the leaders of ISIS: “Leave our children alone.”

Chicago-area Muslim leaders say they’re educating parents about signs their children have been approached online. At the same time, they’re talking about how the FBI uses surveillance and undercover informants.

“We are very frank with the FBI when we meet with them and tell them some of these tactics we are very concerned about,” says Mohammed Kaiseruddin, chairman of the Council of Islamic Organizations of Greater Chicago. “If you find people starting to visit dangerous websites and giving indication that they might go over there [to Syria], other than luring them to go, there should be a program to keep them here and get them on a productive path.”

A judge and community leaders in Minneapolis are attempting that approach with Abdullahi Yusuf, an 18-year-old Somali-American who was arrested at the airport in November as he tried to follow several acquaintances to ISIS-held territory. One of his friends, Abdi Nur, reportedly made it to Syria and has since attempted to recruit others.

Under the judge’s direction, Yusuf has been meeting with educators from a nonprofit called Heartland Democracy. It’s teaming with Somali community leaders on what’s been described as a “deradicalization” program, though it aims to prevent online recruitment in the first place.

“We really start on the identity piece and talking about who you are and how you define yourself and how the world sees you,” says Mary McKinley, the executive director of Heartland Democracy. “If you’re not connected to where you are, you’re going to find something else.”

The pilot program is being watched across the country, but it’s not without controversy and complications. Yusuf was initially placed on home detention, but he’s since been jailed for reasons that haven’t been publicly released. And in April, six more Minneapolis men were charged with attempting to travel to ISIS territory, allegedly with help from Yusuf’s friend Nur in Syria.

The debate over how to handle ISIS recruits has reached the highest levels of the U.S. government. President Obama has called for law enforcement to work with schools, religious leaders, and community groups to win a “battle for the hearts and minds” of young Muslims who may feel disconnected from American society.

But last month Justice Department officials said they were arresting more suspected ISIS recruits out of concern that they could launch “lone wolf” attacks in the United States. Over Independence Day weekend, Abu Qaqa, the ISIS tweeter who allegedly recruited Khan, posted another rhyme that read in part, “It’s 4th of July, try nt 2 die Maskd men wiv guns, planes fall frm the sky.”

“When there are attacks, even by sympathizers with no direct link to the IS, such news becomes effective ISIS propaganda which spreads rapidly across multiple social media platforms,” says Reynolds, the researcher from the University of Central Florida.

On June 25, Khan was back in court for a hearing on the status of his case. Wearing an orange prison jumpsuit and shackled at the ankles, his beard now grown thick, Khan turned and waved to his father. Then he stood straight and listened to the proceedings.

The two sides remained at odds over several issues—including whether Khan’s statements to the FBI were admissible as evidence in court—but Durkin asked the judge to give them another month to keep talking. Hiller added that their discussions included “whether we need to proceed to trial”—an indication that a plea deal could be in the works.

Still, Durkin reiterated his position that whatever prompted Khan to lead his siblings to O’Hare last year won’t be addressed by locking him up. “I still want to get some sort of help for him,” Durkin said.

The judge scheduled another hearing for August, and Khan was led away.  v

Evin Billington helped research this story.