The Congressman's heart is in the right place, but Nichols has zero incentive to name names now. In fact, he has a definite disincentive, since prisons, both inmates and probably guards, have muzzies among them.
The time to pursue this was when the gov't. had something to offer, during the investigation and prosecution.
Now we're starting to see why McVeigh had the speediest execution since the 19th century.