UPDATE BELOW: Former airport shuttle driver Najibullah Zazi—who's accused of plotting a 9/11-type attack on the city using homemade bombs—is set to plead guilty today in Brooklyn Federal Court, law enforcement officials say. According to the AP, there may be a plea deal, and better yet he's cooperating with investigators. Three anonymous sources say the 24-year-old volunteered information during a recent interview with his lawyer and federal prosecutors.

The government has accused Zazi of buying the materials for peroxide-based bombs, which he planned to mix in a hotel room and detonate in the NYC subway system. When he was arrested last year Attorney General Eric Holder called the case the most serious terrorism threat since the Sept. 11, 2001 attacks. But though investigators searched Zazi's car and turned up bomb-making instructions on his laptop (he's suspected of having gotten training at an Al Qaeda camp), they found neither the materials—items from a beauty supply store—nor any actual bombs. With the suspect's new-found cooperation, they hope to find out what became of the explosives.

Last week Zazi's father, who is accused of destroying the chemicals, bottles and other evidence, was released on $50,000 bail. According to the Daily News the younger Zazi is currently in solitary confinement and will plead guilty (it's unclear to what charges exactly) today at 2:30 p.m.

UPDATE: Zazi came clean in the courtroom today, pleading guilty to charges of conspiracy to use weapons of mass destruction, conspiracy to commit murder in a foreign country and providing material support for a terrorist organization. The Afghan native told a Brooklyn judge he went to a terrorist training camp in 2008, made homemade explosives in a Colorado hotel room, then drove cross-country to set them off in NYC's transit system. He says he got rid of the bombs once he arrived in the city, though it's still unclear how. The AP suggests Zazi will cooperate with investigators, but he still faces life in prison without parole at a sentencing in June. "I would sacrifice myself to bring attention to what the U.S. military was doing to civilians in Afghanistan," he told the courtroom.