They have to put the shooting range used for the final test underground not because an outdoor shooting range is infeasible for most police departments but rather because there are a lot less oak trees and thus less acorns and it hugely reduces the chance of trainees and officers randomly panicking and shooting each other.

You can laugh at this policy (how dare you laugh at our hero’s in blue!) but the reduction in accidental gun violence from police in training has been remarkable and police departments are considering trying to do traffic stops in similar underground facilities to reduce the risk to patrol officers actually out on the job.