Whether a final and unanimous, but unannounced, decision by a jury that the prosecution failed to prove a defendant guilty constitutes an acquittal precluding retrial under the Double Jeopardy Clause

1. Whether a final and unanimous, but unannounced, decision by a jury following trial that the prosecution failed to prove a defendant guilty of a charged offense constitutes an acquittal precluding retrial under the Double Jeopardy Clause. 2. Whether a defendant who produces credible evidence of such a final, unanimous, and unannounced acquittal is entitled to a post -trial hearing to substantiate the fact of such acquittal.