MINNEAPOLIS (AP) — After Tnuza Jamal Hassan was stopped from flying to Afghanistan last September, she allegedly told FBI agents that she wanted to join al-Qaida and marry a fighter, and that she might even wear a suicide belt.

She also said she was angry at U.S. military actions overseas and admitted that she tried to encourage others to "join the jihad in fighting," but she said she had no intention of carrying out an attack on U.S. soil, according to prosecutors. Despite her alleged admissions, she was allowed to go free.

Four months later, the 19-year-old was arrested for allegedly setting small fires on her former college campus in St. Paul in what prosecutors say was a self-proclaimed act of jihad. No one was hurt by the Jan. 17 fires at St. Catherine University, but her case raises questions about why she wasn't arrested after speaking to the agents months earlier and shows the difficulty the authorities face in identifying real threats.

Authorities aren't talking about the case and it's not clear how closely Hassan was monitored before the fires, if at all. When asked if law enforcement should have intervened earlier, FBI spokesman Jeff Van Nest and U.S. Attorney's Office spokeswoman Tasha Zerna both said they couldn't discuss the case.