As a former LEO, and without some evidence of extenuating circumstances, I would say the officer was out of line.
While OC spray doesn't affect all dogs, it does deter most.
A witness to the shooting (Mercer) who is not a former owner of the dog corroborates the dog owners' accounts.
Unless the shooting officer can articulate why he feared for his life when a non-growling non-barking dog was deemed a threat to his life, he should be charged with animal cruelty and dismissed.
"He said he kept trying to back away from the dog, but she kept growling, her ears went back and she jumped at him."
That's the cop's story. I think if that is what happened, he was totally justified.
"While OC spray doesn't affect all dogs, it does deter most."
Yep, I used to work at a bicycle shop that sold a brand of pepper-type spray that worked great.
There was an officer at my house the other day checking out my Fiero. My dog was not at all friendly to him at first but warmed up to him after a few minutes. Glad he didn't shoot my dog.
As with most of these stories, we don't have all the facts. My opinion is if (in case of a dog bite) the owner is subject to civil liabilty, then there should be some form of penalty if the "victim" is a LEO.
Since you are an ex cop, and give so much credence to the eyewitness, how many cops did you know who carried their gun in their pocket?