How do police train their dogs to attack?

[Bella Donna]

It seems kinda weird to train your dog to attack on command... how do police do it without making the dog aggressive all the time?

Note: I am NOT trying to make my puppy (5 lb yorkie) attack on command.. I am just curious.

[Teresa V]

Police dogs are trained from the time they are puppies to the time that they are about a year old when they go with their new police owner. The dogs then train with the police officer who is going to be partners with the dog. I have played with a police dog and then been biten by one when I was wearing the protective sleeve. The dog is playful as can be until it put its harness on that it uses on the job then the dog was all work and didn't want to play anymore. This dog was a German Shepard and knew that it was time to work by changing collars or putting on a harness.