What irresponsible parents, and what are they teaching their son? If someone accidently steps on you, just shoot them.
I am not quite sure if that is what parents are teaching him.
Let's not expect from a four-year-old boy to be reasonable in all judgements he makes.
Yesterday, when I went to a symphonic concert to the philharmonic, one of my friends accidentaly stepped on some lady's foot (it was very crowdy and we were trying to find some place to sit/stand). Gee, did she get mad. "Watch your step!!!", she shouted. And all the anger in her eyes and voice... Chill out woman, will ya?
As for the parents having not secured the gun good enough, I agree with all of you. Blatant lack of responsibility.
And the babysitter's had his lesson: "never step on foot of a child you are currently looking after"...