Atticus shoots the dog, and this is when Scout finds out that Atticus isn't just some weenie that sits behind a desk talking about lawyerly things.
She has worried about her father since he isn't tough and he doesn't do anything tough like drive a truck or do outdoorsy things. But as the dog is racing towards her, Atticus reacts calmly and brings the situation to a violent but effective conclusion. In doing so, he reassures scout that he is tough and though it might not always be in the way that she wants it to be or in an outward way, he has all kinds of strength that she just wasn't aware of.
Mr.heck tate was, but it ended up Atticus shooting the dog
Atticus shot the mad dog Tim Johnson.