So if police pilots aren't instrument trained
Approximately 80% of Police pilots are definately instrument trained, because that's the approximate percentage of Police pilots who are ex military. Of the other 20% of "civilian" Police pilots, probably quite a few have an instrument rating from previous jobs.
Regardless of which, we have to carry out 1 hour of sim IF training every 3 months. Not a great amount, I must admit, but enough to prepare you incase of inadvertant IMC.