Under both state and federal law, defendants in a criminal case have a due process right to obtain any evidence in possession of police or prosecutors that is favorable to the defense. If the prosecution fails to turn over such information, it may be sanctioned for this violation.
In California, defendants have an obligation to turn over some information to prosecutors as well. This includes (1) the names and addresses of all people (other than themselves) who they plan to call as witnesses; (2) any relevant statements made by any of these witnesses; (3) any experts’ reports; and (4) any real evidence that they intend to offer into evidence. Outside of these four categories of information, defendants are not required to turn over evidence or information.