It says secret clearance but is it based on a T3 or T5?
Also do they fill out the sf86 or a police packet like local police departments?
DoD Police normally start with a Tier 3.
The paperwork is the same for a Tier 3 or 5, the difference is the depth taken to find/validate the information and your risk potential.
The normal police background investigation is normally equivalent to a medium to high risk public trust investigation.