Oh..from an Attorney Site..concerning securing tapes for your defense...
DO NOT DELAY IN HIRING AN ATTORNEY. A qualified attorney can assist in obtaining a low or personal bond if retained by arraignment. Further, your attorney can provide immediate review of the case for defects, move to suppress evidence, and compel the prosecutor to share vital information they intend to use against you. Your lawyer can prevent important evidence such as 911 tapes, police dispatch tapes, vehicle information, etc. from being lost by delay. Some evidence is only kept for a short period before it is recycled or destroyed.
911 tapes are often reused/recycled every 30 days