You mean 460 MHz, correct? The only 450 MHz freqs I see in the database are for fire and public works. I live too far away to monitor Stuttgart, but these are the freqs posted:
460.35000 POL DISP Police - Dispatch
460.17500 POL CAR Police - Car-to-Car
If the above are correct, a PL/DPL submission would be nice.
;^>
Note, I did say posted. Several years ago I visited Sheridan, and the freqs posted were not exactly correct, but a search did find the correct freqs the PD and SO were using at the time of my visit. It has been a few years since I've been there, so I do not know if the freqs I have for Sheridan are still correct. So, I will search again, if the freqs I have are silent the next time I am up that way.
So to find what Stuttgart is using, you should do a search of the 460-461 MHz range and a search of AWIN and try to identify unknown talkgroups. Check the antennae array, if more than one on the police cars. The size and shape of them will help you tell if you should be checking VHF, UHF, 700-800 MHz, or all of them. Be aware that some agencies are using, what I call Yatzee Cups (Large-VHF, Medium-UHF, and Small/easy to grip like a push rod-700-800 MHz, Fins, or Hockey Pucks.)
Another reason they may be "silent" is they are using MDTs (Mobile Data Terminals), which are not monitorable. Many agencies have begun using them. So, it may seem that the primary freqs are not in use when most of the activity is "silent". Plus, don't forget that many officers will communicate amongst themselves via cell phone (much to the chagrin of their supervisors).
Hope this helps.