If any one of the allegations were used in the indictment or trial of the agents, they need a new trial. I'd think that would have some effect on the guilty verdict.
1. confessed to knowingly shooting at an unarmed suspect;
2. stated during the interrogation they did not believe the suspect was a threat to them at the time of the shooting;
3. stated that day they "wanted to shoot a Mexican";
4. were belligerent to investigators;
5. destroyed evidence and lied to investigators.
I note that DHS has not yet said the claims were false, just that they cannot turn over investigation paperwork proving the claims were true.
I believe the DHS said it didn't exist, so you're right, they "could not" turn it over. Kind of begs the question, how did those allegations get into the stream of evidence that indicted and convicted the two agents?
Kind of hard to argue good intentions, here. Kind of hard to argue for a fair trial, too.
I think Sutton said he didn't use ANY investigation papers in the trial, only actual testimony. If a person testified at trial to something under oath, it won't matter that they don't have the notes of the original meeting where they found the information.
If the notes were introduced in the trial, then they would matter, but they would then be exhibits and would be on file at the court, so I don't think that's the issue.
If someone testified at trial that they overheard the men say something, it really doesn't matter if the notes the DHS had where the man told DHS about it are still around.
That's why I said it's a "PR" problem, because the promise of notes seems to be related to the post-trial political battle, not the trial itself. The actual appeal of the case is decided in the court system, not the court of public opinion -- at least that's what the conservative view has been in the past.