What is Brady and why is it important?

Brady evidence comes from the case of Brady v. Maryland, 373 U.S. 83 (1963), which held that due process requires that material, exculpatory evidence be provided to the defense.

To show materiality, the defense must show that if the evidence had been disclosed, that the result of the proceeding would have been different. This has been stated in another way: whether there is a "reasonable probability" that the defendant received a fair trial without the evidence or the suppression of the evidence undermined confidence in the outcome of the trial.

There is no Brady violation if the defense could have obtained the evidence through reasonable diligence. 

Brady is important because in most, if not all cases, the government does the initial investigation and "controls the crime scene." They get the first crack at the evidence, decide what to collect, what not to collect, who to talk to, what to photograph, what to test, etc. The defense may not get access to these materials for weeks or months. For some of these cases, time may be of the essence as memories fade, evidence degrades, automated surveillance video is recorded over, or any number of things that happen due to the passage of time. 

Brady, when done properly, will prevent the government from hiding evidence. One common form of evidence that is helpful to the defense is called impeachment evidence. That is evidence that shows the witness has been dishonest in the past. Of particular importance in most criminal cases is when a police officer in most has been dishonest.

In a recent LA Times article, the authors depict how one officer's act of dishonesty was kept hidden and how that impacted numerous cases.

Some prosecutors' offices have "Brady lists" which are lists of police with known issues that can be used as impeachment evidence. However, getting accurate Brady lists can be more difficult than one may imagine due to the secrecy around officers' disciplinary records. The police are generally in charge of policing themselves when it comes to allegations of misconduct. The problems with such a system of trusting any organization to police themselves should be understood, but they may be especially problematic if the particular agency has an "us" vs. "them" (them being normal people) attitude or act as a para-militaristic organization as opposed to an agency that is there to protect you (the normal person). 

Also, inherent in the "police yourself" problem is the tit-for-tat, if you scratch my back, I'll scratch yours, which breeds self-dealing and corruption. There is also a fear of retaliation for speaking up.

So, because only certain classes of misconduct will be reported and only if the misconduct is established beyond a certain threshold, will the information qualify to make it onto a Brady list. 

The spirit of Brady is in the right place, but, like many aspects of the justice system, the way it plays out in the real world may not be so righteous.