After hearing about the shooting of a dog in a public park, I fully stand behind the actions of the man who shot the dog.  I'm sorry for the dog owner's loss, but in this case they were totally in the wrong and should have taken precautions to protect and be considerate of others.  For starters, they did not have the dog on a leash.  They also did not restrain the dog when it jumped at the man and he repeatedly asked them to restrain it.  With so many dog attacks resulting in deaths recently, I can understand the man's concern and he acted to defend himself quickly.  This was the dog owner's fault entirely.