What I'd like to know in this situation is how the cops were able to determine the firearm-wielding neighbor was a "good guy." Unless they had the perp in full view during the entire chase and observed the neighbor coming out of his house to hold the perp until the cops could catch up, how do they know the neighbor isn't an accomplice or something? I'd be hesitant to come out of my own house with a firearm while such a chase was going on, for fear I'd get shot in the confusion.