Mental Health Issues And Witness Credibility: Learn More About Why It's Important And What You Can Do

Posted on: 22 November 2016

If a prosecution witness is suffering from any serious mental illness that could make his or her testimony unreliable, should the defense be told in advance? Absolutely. Prosecutors are supposed to disclose anything that could cast doubt on a criminal defendant's guilt. Learn more about how the mental health of a witness could be an issue in your case, why the prosecution has a duty to disclose anything it knows, and what you can do to help yourself.

The Right To Full Disclosure Of Evidence

Many criminal trials start off with the defense not knowing exactly what evidence the police do or don't have against a defendant. Sometimes you can get a good idea by listening to what the police say that they have—although the police are allowed to lie to you during an investigation. You really can't be sure what evidence is being used—including what witnesses are going to testify against you—until after you're charged and your right to the full disclosure of evidence kicks in. 

The prosecution has a duty to turn over not only incriminating evidence to the defense but evidence or information that could be exculpatory—which is another term for evidence that could cast doubt on your guilt and lead a jury to declare you "not guilty." This is a longstanding rule in the U.S. legal system that's known as The Brady Rule, after the case that gave it its name. That includes information the prosecution knows about the potential reliability of a witness.

The Flaws In The System

Unfortunately, the prosecution is the one who has the right to determine what it is and isn't required to disclose. When the process breaks down and the prosecution doesn't make a good call, the burden falls on the defense to prove that the information should have been disclosed and that there is reasonable probability that, if it had been, the outcome of your trial would be different.

This leads to situations like that of the conviction of Ricardo Salas, of California. Salas was convicted of murder based on the statements of a key prosecution witness: a schizophrenic off his medication when he testified. Salas ended up being sentenced to life without parole. Now that the information has come to light, the defense is seeking a new trial, which could likely have a very different outcome.

The Importance Of Communication 

Criminal defendants need to be aware of the possibility that a defendant's testimony could be excluded based on mental issues because defendants may be the only people in a position to alert their defense attorney to a potential problem with the witness. Simply put, you may be in a situation where you know more about the potential witnesses against you than your defense attorney does. Never assume that he or she has been informed of those facts by the prosecution.

In the Salas case, for example, the witness was a jailhouse informant that was purposefully put in the defendant's cell in order to gather information. It's likely that that the defendant observed first-hand some signs of the mental instability the witness was suffering. 

If you think that you have information about a prosecution witness that could help your attorney cast doubt on his or her reliability, make certain that you discuss the situation as soon as possible. For more information or help, talk to a criminal defense attorney today.