If you are referring to Brady material, as that term is used in the criminal justice system then yes -- the Brady disclosure rules are applicable in both systems. If someone is telling you otherwise, remind them that Brady was a United States Supreme Court case and its applicability is universal -- then ask them why they don't think that is the case.
In no way am I offering you legal advice, and in no way has my comment created an attorney-client relationship. You are not to rely upon my note above in any way, but insted need to sit down with counsel and share all relevant facts before receiving fully-informed legal advice. If you want to be completely sure of your rights, you must sit down with an experienced criminal defense attorney to be fully aware of your rights.
Brady is a rule of federal constitutional law pronounced by the United States Supreme Court, and it applies to all criminal proceedings, state and federal. Details of discovery practice vary between states and between state and federal courts, but the Brady requirement is common to them all.
Yes, Brady applies to both state and federal courts. The Brady case, stands for the proposition that the prosecution must disclose exculpatory evidence to the defense. Exculpatory evidence is evidence that would have made the conviction or sentence different had the exculpatory evidence been released.
Marijuana is against federal law. Federal law supersedes state law. A person could be charged and convicted for marijuana related crimes such as possession, cultivation, distribution, manufacturing, transportation, and conspiracy.