Your Pro-89 is not a trunk tracking scanner.
The system in Caddo parish is a Motorola Type II. An easy system
to program with the right radio.
The best you can do is enter all 25 freq.'s and try and follow the
conversation although it will be difficult.
Save the Pro-89 for the races and get yourself a trunktracker,
either a Pro-95 or Uniden's BC245 XLT if you don't need digital capability.