My favourite subject: Lots of things to consider here. The first one is how importantly the constabulary views the bike as policing tool! If it's important to them and they happen to have keen cyclists high enough up the decision making structure then You tend to get the right bike, uniform, equipment and training for the job. If not, then your in my Constabulary!
The MTB is generally the best bike for the job because they are robust, easy to ride, easy to buy etc. A lot of Police officers and PCSO's haven't ridden bikes in years, so they are generally nervous, self conscious and unfit. MTBs are a good bike for all round use.
Would 29ers with semi slicks be better? Do they need front suspension. How about a cyclo cross bike. What about SPDs. All depends on where you Police and at what level your riding is at. A cyclo Cross bike would be great for me in the flat urban area of East Abglia I work. If I was the Beat bobby for Gaotland up in Yorkshire I may want something a little more robust!
There is the Kudos factor, but most kids on my patch think Claud Butlers are the best thing in the world. What they would make of a Cannondale Badboy with lefty fork, fully marked up with Blues, Twos and Sirens.
If I can't have my Cyclo Cross bike then a rigid 29er on semi slicks would be my next choice!
Emergency Service Cyclist Forum