Shannon Maureen Conley was just 19, barely out of high school and a convert to Islam, when she fell in love with a Tunisian man who said he was an Islamic State fighter in Syria. And, according to a criminal complaint, she wanted to leave her Denver suburb and join him.

Over the course of five months, the FBI talked to Conley nine times, trying to persuade her not to go to Syria.

But it didn't work. According to a local news report, her father tipped off the FBI after he found her one-way ticket from Denver to Turkey.

Conley was arrested boarding that flight at Denver International Airport. She subsequently pleaded guilty to a lesser charge and now faces up to five years in prison. Her sentencing is scheduled for January.

Her case raises a new question for law enforcement about how to handle cases of Americans who seem more naive than an actual terrorist threat.

In another case, three Denver schoolgirls were recruited by the Islamic State, also known as ISIS, on social media.

The girls are minors — 15, 16 and 17 — and the Justice Department says because of their age, it is unlikely they will face charges for leaving the U.S. to join a terrorist group. But if they had been adults, that might have been a harder call.

U.S. officials say that many Americans are going to Syria for humanitarian reasons, or even for love.

And that makes the decision about charging people with terrorism offenses very murky.

Should They Be Charged?

"Should they be prosecuted, should they be counseled, should they be reintegrated in a more compassionate way?" asks Juan Zarate, who used to be a terrorism official at the Treasury Department. He's now at the Center for Strategic and International Studies.

"Those are important questions because to the extent they are not fully radicalized, they perhaps were lured by a romanticized vision of what life was like in Syria," he says. "Maybe it is appropriate to apply different tools and measures to peel them away from the movement as opposed to the same tools we have applied to more hard-core members of the group."

For years now, the Justice Department has been using a charge called "material support" to prosecute anyone who helps a terrorist organization.

The statute is purposely vague and has been a catchall that the government uses to prosecute anyone with even a tangential link to a terrorist group.

But U.S. officials say the people heading to Syria present a more complicated case. And that means prosecutors may want to get away from a one-size-fits-all response.

"I've always felt latitude that we need to approach these cases individually," says John Walsh, the U.S. attorney for Colorado, who handled both the Conley case and the three schoolgirls.

"Once someone has actually committed a crime, of course we have look at that and have to make an assessment and make a prosecutorial decision," he says. "I'm not going to speculate on what might happen in the future with these cases, but part of the reason we are working so hard to get information out to communities is to make sure that doesn't happen."

Working With The Community

The reasoning is that if the U.S. doesn't throw the book at everyone who heads to Syria, communities might be more willing to identify someone who has left.

"As a country, we haven't figured out, and certainly the Muslim communities at risk haven't figured out, what an intervention strategy really looks like," says Zurate.

The FBI, for its part, is looking for middle ground.

Last month, FBI Director James Comey hinted at the possibility of more options, though he wouldn't say what they were.

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