I don't think handling has much to do with it.  Most of the time police departments want body on frame for their cars since they can take a beating better than unibody.  Since the big body on frame cards tend to be RWD, that'd be why there are more RWD versus FWD used in the past.  This is changing with the death of the big American sedan.

Most of the taxi's around here are retired police cars. They are cheap, already set up for propane, and easy to work on. The plant that produced Crown Vic's, and police specials is just outside of London and put a lot of people out of work when it closed it's doors.

Oversteer is preferrable because it's easily controllable with throttle.  As a former race driver in the amateur ranks, I can drift a RWD esaily, but not so in a FWD.

Have you ever seen a FWD race car?  None exist that I know of.

RWD is also simpler - engine thru clutch or torque converter, straight to transmission, then thru a drive shaft to differential.

FWD is mechanically more complex, combining transmission and differential into one unit.  Hence, it's less reliable, and more expensive to repair when needed.

I won't have a FWD car for my personal car, and until they quit offering manuals, I don't have an automatic transmission either.  I prefer to control the car rather than having it float along on its own accord.

I personally think it has to do with not only cost of repairs, but how much of a beating it can take before needing repairs. Having worked on cars for 23 years, I can say that older rear wheel drive cars have a much beefier front suspension. Occasionally, on a rear wheel drive car, you might need a ball joint or a tie rod end or a set of shocks replaced, but that's about it. On front wheel drive cars, you got ball joints, tie rods, axles, struts, strut mounts.....and the ball joints and tie rods are made cheaper and smaller than they used to be. They break easier, yet cost more. Struts nowadays cost 4-5 times what a set of shocks costs. Axles--$200 a pop or more. Not to mention the cost and labor involved when changing wheel bearing assemblies, which take a real pounding on police cars. And front wheel drive cars nowadays seem to be mostly mid size. Gotta have room to haul them criminals around, and enough power under the hood to catch them.

Around here the LTDs are being replaced with mid size SUVs. The cops love them stating that they can see better and carry more. Most are RWD fords

For what it's worth (I well know I'm on the other side of the Ocean)

FWD Vs. RWD is a bit like the "slabsides vs. wheelgun" debate among LEOs.

Most Police Agencies here in Europe either go with BMW 325 (because they're compact, fast and reliable) or will but whatever the national industry has to offer (i.e. the French will buy Peugeot or Renault, the Italians will buy Alfa Romeo, many others have Toyotas built in the UK)

Early Police Alfa Romeo Giulia, 1600cc, 130bhp, RWD
Alfa Romeo 156, 2000cc, 155bhp. FWD
Alfa Romeo 159, 2400cc Turbodiesel, 210 bhp, FWD

Pug, Renny, Alfa all offer 200bhp+ cars in FWD only, with a 6-speed manual. Come to think of it, Skoda offer a 4x4 sedan built on a modified Audi floorpan.

The point is nobody will design and manufacture a car for Police purposes only, so the Police buy what's avaliable on the market.

In general terms, FWD may appear to be more complicated, the truth is it's all concentrated on the front axle. The rear axle is there for support and nothing else.

RWD will give oversteer and allow for "Dukes of Hazzard" U-turns, but in tight, twisty environments FWD is more manoeuverable and more forgiving.

A high speed chase in the rain ? Give me FWD any time.

Last, "fishtailing" the fugitive is against the rules by European legislation, you can't ram the fugitive's car unless you are trying to avoid something much, much more lethal. on the other hand, we don't "chase at 40mph", we chase, hunt down and stop, period.

The pit & ramming are for from equal. A pit can be done with almost no damage at all., Both cars will drive away from a properly done pit,