Very sad, even tragic story, DR Druxy.
I read stories like this a lot, as well, and I always wonder how accurate the reporting is...for instance, was it truly a therapy dog, or was it acutally a mean, gnarly dog and the angry citizen just wanted sympathy from the reporter (and you rarely ever read an update).
There are always two sides to every story, and then there is the truth. Maybe it is just that I can't imagine anyone shooting a dog unless they honestly felt their life or someone elses life is in danger. On the other hand, it is certainly possible that some officers aren't as upstanding as I expect them to be.
Very, very sad either way. And if it ever turned out that the officer had no real reason to kill the animal, then I would throw the book at him/her!!