The evidence is the heart of any criminal case. We usually think of evidence as evidence that supports (or proves) the allegation that the crime was committed. This is technically called “inculpatory evidence” as it tends to incriminate (or inculpate) the defendant. But what about evidence that tends to exonerate (or exculpate) the defendant? This evidence is called “exculpatory evidence” but it seems we hardly hear about this type of evidence.
In the seminal case, Brady v. Maryland, 373 U.S. 83 (1963), the United States Supreme Court held that in any criminal case, the prosecution has a constitutional duty to reveal to the defense any evidence it has that might show the defendant is innocent of the crime charged or did not commit the crime in the manner charged. This is the defendant’s due process right. This is commonly referred to as Brady evidence or a Brady disclosure and it applies to all California criminal cases.
Brady evidence can be physical evidence, witness statements, video footage, recordings, or any evidence that has a “reasonable probability” of establishing that the defendant did not commit the crime or did not commit the crime to the level charged (for sentencing mitigation purposes). A good example might be evidence that a credible witness to the alleged crime comes forth and states that he saw the police plant evidence. If this were a true statement (and it certainly happens, as the recent incidents in Baltimore have exposed), it is exculpatory and the prosecution must reveal it. But the police would certainly try to cover this statement up, sometimes even with the help of the prosecutor. Hopefully this doesn’t happen often, but it is unfortunate that the prosecution and the police sometimes do suppress exculpatory evidence in furtherance of their own prosecutorial agenda. Orange County had its own Brady evidence scandal a few years ago.