I agree wholeheartedly that this dog should not be killed, but back at work?
A well trained working dog waits for a command from the "handler" before acting. I don't believe the dog should have bitten the boy - period. Further, I think the dog should be retired, and rehomed with a person or family who will allow him to be a cherished family member - a dog, not a tool.
He cannot remain as an active working dog for the police, with a muzzle on, as I have heard suggested.
I also disagree with dogs being kept in pens - double locked or otherwise.
From experience, while living in Vancoouver, I saw a police officer let his dog go after a "suspect" who ran arouind a corner. The dog then grabbed and dropped to the cement the first person in it's path. I don't know what happened to this dog.
Another incident I am aware of involved a young mentally ill man, who had committed no crime, but was running away from the police in fear - the police dog grabbed him by the face, and chewed on him.
I see that young man occasionally, and he has permanent, disfiguring scars on both sides of his mouth.
I don't know what happened with that dog either.
Many "working dogs," and I will include assistance dogs in this, live lives of quiet desperation.
Severely trained, they often wait motionless for hours for their person to make a demand on them.
Some of these dogs are treated splendidly, enjoying daily play and rest time, and enjoying their work time too (I think), but others are thought of as "extensions of me", "extensions of my wheelchair", etc.
A dog is not a tool or a weapon.
A dog is a living spirit, the same as you and I.