In the 16-page appeal, the U.S. attorney's office is asking a federal judge to overrule a decision by a magistrate judge Thursday to release Abdella Ahmad Tounisi, 18, to home confinement.
"These facts only reinforce the presumption of dangerousness," the U.S. attorney's office says in its appeal.
Prosecutors want Tounisi to remain in custody on charges that he provided material support to a terrorist organization. He has been in custody since his arrest April 19 at O'Hare International Airport.
Prosecutors allege that Tounisi posted messages on a phony website set up by the FBI agreeing to travel to Syria to fight with the Al-Nusra Front militant group. According to authorities, Tounisi has links to a second Chicago area terrorism suspect, Adel Daoud, who was arrested in September after he tried to set off what he thought was a bomb outside a downtown bar. The two were close friends and plotted the bomb attack together, prosecutors allege, but Tounisi backed out when he suspected law enforcement was on to them.
In ordering Tounisi's release, U.S. Magistrate Judge Daniel Martin repeatedly called the decision a "close, close" call but said that pretrial detention is intended to be an "exceptional step." Martin also said he was convinced in part by a courtroom packed with family members and leaders from Tounisi's religious community. The judge also cited Tounisi's lack of criminal background.
Martin's voice shifted to a stern tone as he directly addressed Tounisi, warning him not to break any of the rules he had set for his release. Martin acknowledged the rare opportunity he was giving him, noting the seriousness of the charges and the allegations that Tounisi intended to harm people here and abroad.
"This is no game, Mr. Tounisi," Martin said at one point. "The world is a very volatile place. … Right now you are hanging by a thread in this courtroom."
Martin named Tounisi's father to act as custodian to ensure his son followed the court's orders.
In their appeal, prosecutors say Tounisi has shown himself to be dedicated to terrorism and that his family cannot be trusted to keep watch over him.
They note that Tounisi's involvement in the bomb plot "reveal much about his worldview. But perhaps even more revealing is the fact that none of this deterred the defendant from attempting to travel overseas to join a terrorist group.
"If ever the defendant experienced a wake-up call, surely it would be when his good friend was arrested on terrorism charges for a crime the defendant helped plant," the appeal states. "That the defendant continued to pursue this path in the face of the FBI's scrutiny speaks volumes about his history and characteristics.
"Neither the defendant's parents nor the FBI was able to shake the defendant from the path that led to his arrest."
A judge is to hear the appeal later today.
On Thursday, Tounisi maintained a serious, slightly worried look in court. He spoke little — only to acknowledge that he understood what was happening.
Tounisi's attorney, Molly Armour, denied he posed either a flight risk or danger and noted that he had never before been arrested.
"The word 'terrorism' is a word that tends to taint everything it touches," she said. "But it is the American system that requires us to look at the individual."
Armour said Tounisi, a U.S. citizen, has a close, loving relationship with his family. She said they do not have the financial resources to help him flee Chicago and that he had already tendered his passport.
Armour said the approximately 30 supporters in the courtroom had pooled together $1,200 for Tounisi's bail. They also brought a steadfast commitment to ensure his obedience to the court's rules, she added.
"We present a community of people who care for this young man," she said.
Karen Greenberg, director of the Center on National Security at Fordham University, said she could recall only a handful of cases nationally in which suspects in terror-related cases had been released pending trial, saying judges have taken a universally tough stance with suspects.
"At some point we're going to figure out how to have gradations of severity from one kind of alleged involvement in terrorism to another," said Greenberg, who was not commenting on Tounisi's case. "It will show up in detentions and sentencings first. And we haven't seen it yet."