Discovery in criminal cases:

The act of the defense obtaining information before trial through demands for production of documents, depositions of parties and potential witnesses, written interrogatories (questions and answers written under oath), written requests for admissions of fact, examination of the scene, list of law enforcement agencies and the petitions and motions employed to enforce discovery rights, as in disclosure of co-operating individuals CI’s, (informants) tape or video recordings. The theory of broad rights of discovery is that all parties will go to trial with as much knowledge as possible and that neither party should be able to keep secrets (trial by ambush is not permitted)  from the other side (except for constitutional protection against self-incrimination). Often much of the fight between the defense attorney and the prosecutor takes place during the discovery period.

If you've been accused or arrested, you cannot afford second-best representation. Consult certified criminal defense attorneys.