Six days after September 11th, FBI agents tracking a suspected terrorist raided a Detroit house and stumbled upon three North African immigrants living in the apartment upstairs. The man the FBI was looking for had moved out. But a sweep of the apartment revealed something suspicious — two old airport badges and fake identity documents.

That was evidence enough for an arrest. But there was more: videotapes of tourist destinations and a suspicious day planner with hieroglyphic-like scrawls and cryptic references – apparently, to a Turkish airport and a Jordanian hospital. Once the prosecution produced a witness to lay out the conspiracy, a jury was convinced. Two of the men were convicted on the most serious charge, that they intended to provide material support to terrorists.

But the real transgression became apparent only later. As the men waited to be sentenced, the federal judge presiding over the trial discovered that key evidence that might have impeached the government’s star witness and cleared the defendants of wrongdoing was never turned over to the defense. What followed was an investigation of the prosecution, one that turned up startling evidence of its own.

Retro Report lays out this story using declassified documents and interviews with those at the center of the case, and asks not only how this travesty could occur after 9/11, but how unlikely it is that such a distortion of justice could happen again today.