Reply #10: It "could" apply to any criminal case.

[Hepburn]

The prosecution is MANDATED to turn over to the defense any exculpatory evidence/materials.

This rule came from Brady v. Maryland. Here is a wiki link to a reasonable discussion of the case. I usually do not link to wiki, but unless you have a legal background, just reading the case most likely would not make a ton of sense and this is a fairly decent explanation:

http://en.wikipedia.org/wiki/Brady_v._Maryland

So in the instant case ~~ if the US was in possession of ANY materials which would lead to any reasonable inference that the defendants were innocent, they must turn it over. If later discovered that the materials were in the possession of the prosecution, usually a dead bang winner on overturning a conviction, or in the case of Brady, the sentencing portion of the process.

Thus, for example, if there was any link with US government officials, etc., these "could" be Brady material.