Under the United States Constitution, prosecutors have an obligation to turn over potentially exculpatory evidence — whether it is evidence that is directly favorable to the accused and unfavorable to the government’s case, or evidence that undermines the credibility of the government’s witnesses.

But, as our kind host frequently discusses, there’s a broad gulf between what should happen and what does happen in the criminal justice system. Prosecutors withhold exculpatory evidence all the time, usually without consequence.