What is the best police dog breed?

It depends on what they are used for. A tracking dog - bloodhound Detection dog - Labrador patrol (bite dog) - Belgian Malinois, Dutch Shepherd, or German Shepherd Usually, it's not a particular breed, but bloodlines of a breed that are the best. Police dogs are usually bred specifically for the type of work that they will be performing. It's similar to breeding show winning dogs. You would use the best of the best for breeding, then take the ones from the litter that show the most promise, and start training from there.

Other contributors have said:

Usually, German Shepherds. They are very good attack dogs. Hope this helps!
Well there isn't a specific breed policemen like, but most police dogs are German shepherds or Labradors.
German shepards

Another popular kind is the Belgian Malinois. They look like German Shepherds but are a little smaller and faster. And not quite as handsome imho.
Police use different breeds, depending on what they'll be using the dog for (tracking, scents, ect). While the most common is the German Shepherd, Belgian Malinois', and Blood Hounds are also used. Even the Beagle is sometimes used for drug detection. Hope this helps.
German shepherds are the most common but some use other breeds like labs or mixed breeds.
The most commonly used police dog is the Belgian Malinois (90% of the world's military and police units uses them).

The next most popular dog used (9% of all military/police units use them), is the working-line German Shepherd (which is completely different from the normal or "show-line" German shepherd).

The third most used police dog is the Dutch Shepherd, which is pretty much a Belgian Malinois with a brindle coat.
Fierce or brave type of dog are used police dog
Usually a German Shepherd