HELP!!! neighbor's dogs can i shoot them?

My neighbor down the street has 2 pitbulls that they just let run rampant in the neighborhood. My uncle waits outside everyday to go to his senior center and the dogs always come in our yard and bark at him. It really worries me because he is handicapped and cant defend himself against these dogs. We've told these people time after time to get a handle on this but they arent being neighborly and handling their responsibility. We warned them my next step WILL be getting my shotgun and blowing these mongrols away if they come near my family again. What do you think?