I have a 2018 PIU, and the Police Engine Run button and system is built in from the factory. The switch from that is located on the left side, below the parking light/headlight control knob. You push button, remove key, exit and lock up. It leaves engine and all accessories running, but locks window switches and other controls inside vehicle. Key must be reinserted and turned to disengage system.
These red aftermarket switches were likely added on to unlock the shotgun/rifle rack or something along those lines. Toggle switch activated at beginning of shift, then push button activated at time of need to retrieve long gun. There are various methods to accomplish this and each department wires their vehicles as they will.