I haven't read the complaints or Indictments as they are not on PACER yet, but the article says investigators believe all three attended an al Qaeda training camp in 2008 and that both have been under surveillance since Zazi's arrest. Also,

Authorities searched Medunjanin's home on Thursday afternoon and seized his U.S. passport. Medunjanin then got in his car and began racing through the streets of New York at speeds of up to 90 mph/(145 kph), according to a law-enforcement official with knowledge of the investigation who spoke on condition of anonymity.

"He called 911 (the emergency response line) and invoked the name of Allah. He said, 'We love death more than you love life!' and rammed the car in front of him," the law enforcement official said.

CNN adds:

When Medunjanin's attorney, Robert Gottlieb, was asked about the message, he told CNN: "That particular comment had nothing to do with terrorism."

"People say things consistent with their upbringing, their background, their beliefs that if you want to misinterpret, you can for your own purposes," the lawyer said. "I have nothing more to say about it at this time."