When a person is charged with a crime, the prosecution is bound by law to provide all the evidence supporting the charge or charges, including evidence that might exonerate the defendant. Evidence that is favorable to the defendant is called “exculpatory evidence” and back in 1963, the United States Supreme Court held that the prosecution must give all this exculpatory evidence to the defense. This case, Brady v. Maryland, 373 U.S. 83, was the seminal case on exculpatory evidence. These days, attorneys refer to Brady evidence when they are talking about exculpatory evidence.
Unfortunately, the prosecution sometimes plays fast and loose with exculpatory evidence. And if the defense doesn’t know the evidence exists, it may be hidden by the prosecution and not available in the discovery, leaving the defendant at a disadvantage. This doesn’t happen in every case, most prosecutors run an honest practice, but it happens. A few years ago, the Orange County District Attorney’s office was scandalized by allegations that it withheld material evidence from the defense and the court in a high-profile murder case. That led to a new law in California that provides for criminal punishment of a prosecutor who withholds evidence.
Sometimes, the discovery that a prosecutor has withheld exculpatory evidence does not become known until years after the trial. For example, just this year, disciplinary charges were filed by the State Bar of California against a former L.A. City Attorney who was accused of withholding potential exculpatory evidence in a murder case that took place 30 years ago. The case was a death penalty case and the defendant was convicted and sentenced to death.