The special prosecutor investigating the shooting death of unarmed Florida teenager Trayvon Martin has ruled out using a grand jury in the case, meaning her office alone will decide whether to charge shooter George Zimmerman with a crime. The decision means Zimmerman will not be charged with first-degree murder — a serious charge that would indicate the crime was premeditated and would require the convening of a grand jury in Florida. The special prosecutor, Angela Corey, said her decision “should not be considered a factor in the final determination of the case.”