Here’s a case discussing access to mental health records of a primary prosecution witness.
This was a due process and confrontation case. Here, as is not an infrequent issue, the prosecution succeeded in having damaging information about their witness excluded. The prosecution then went on to give an “incomplete and inaccurate picture” of their witness. The prosecution did this knowing full well that they were presenting a misleading picture. (Why that’s not prosecutorial misconduct I have no idea. [N.1])
The majority held that the Confrontation Clause was violated by the restrictions on cross-examination about the informant’s mental health and use of prescription medication. The jury was deprived of evidence concerning his ability to perceive and recall what transpired and the informant’s credibility. On this point, the majority noted:
“Had the jury learned that the CI had recently admitted to ‘hearing voices,’ ‘seeing things out the window that [were] not really there,’ and experiencing suicidal ideation, it could have reasonably concluded that the CI had a reduced capacity to observe, remember, and recount. Absent the district court’s restrictions on cross-examining the CI about his hospitalization, Robinson would have likely revealed these problems with perception and narration, along with the CI’s ‘long history of mental illness.’”
Robinson, _ F.3d at _.
Defense, when this happens you have to raise the issue on a 39(a) after the witness has testified. It is common to have evidence excluded in a motion in-limine pretrial. But once the prosecution opens the door you need to ask the judge to reconsider her decision.
N.1. I think this is misconduct because the prosecution’s presentation lacked candor and was knowingly inconsistent with the facts known to them. The prosecution knew that there was damaging evidence and yet they deliberately set out to cast their witness in a good light, knowing full well the judge was preventing the defense from challenging the prosecutions characterizations. If the prosecution wants to have something ruled off-limits, then it’s off-limits to them as well.