Where in the story does it say it was aggressive? You see, that’s the problem. This is a poorly written story with no history on the dog except it “ventured into his yard several times.” Not enough info.
it also says he called the “investigators” (sheriff?) a couple times. you don’t usually call the cops on a friendly dog.. well it is a mastiff, he might have been complaining about the enomous poops. :)
Doesn’t need to be. Would you let a gang member in your yard if he wasnt acting aggressive? Dogs like that often turn on little kids in their owners family. Why on earth take a chance?