The best answer to this question lies in the state rules of criminal procedure. In general, prosecutors have a higher duty to turn over all evidence, especially exculpatory evidence (evidence suggesting the defendant did not commit the crime).
A Defendant does not have a responsibility to turn over evidence. The Defendant has the right to remain silent, sit there and do nothing and tell the prosecutor to do his own investigation and prove the elements of the crime.
The best thing to do though is discuss what "evidence" a person may have with an experienced local criminal defense attorney. A party or lawyer's obligation to turn over evidence and the discovery rules are in your state rules for criminal procedure.
You may even want to read through the Tennessee Rules of Criminal Procedure:
In Memphis, the state is going to put on the bare minimal proof to make probable cause which could be one witness. The judges do not require much to bind over.
Claiborne H. Ferguson, Esq. is * Certified as a Specialist in Criminal Trial Advocacy by the National Board of Trial Advocacy. * Certified as a Specialist in Criminal Trial Advocacy by the Tennessee Commission on Continuing Legal Education and Specialization.
The DA need not put on all its evidence at the prelim but must divulge to the defense all evidence, exculpatory included , before trial and soon enough to allow the defense to investigate.