K-9

I see K-9 units with a certain frequency. Which got me thinking. Police dogs can be useful in various ways. For instance, bloodhounds can sometimes be helpful in finding a lost child in the woods. 

Police dogs are also useful in tracking or apprehending a fleeing suspect. They can outrun a suspect. And because they track the suspect by scent, they can locate a suspect in the dark, or hiding in the bushes. The suspect is invisible to the police, but detectable to the dog. 

But that raises a question. At least in movies, bloodhounds are given an article of clothing worn by the missing person. They track someone with that specific scent.

But when police turn a German Shepherd or Malinois loose to hunt down a fleeing suspect, the police dog doesn't know what the suspect smells like. He's not pursuing an individual with that unique scent. Rather, it's whoever happens to be in the vicinity. Whoever he encounters first. It could be a five-year-old boy or old women walking home from church. 

Isn't it inevitable that many innocent bystanders will be bitten or even mauled by police dogs? 

Keep in mind, to, that it's a felony to harm or kill a police dog. So an innocent bystander can't even protect himself. In that situation, self-defense is a crime.