Why did Brigade wait so long to hunt Frank?
I have watched the film 5-6 times. Usually casually but I swear I do not remember this being explained. Did he not know where to find Frank and then the opportunity comes forth where he realized he could bait him by taking his brother into custody?
According to Frank he had killed Brigade's wife so long ago he almost forgot about it. Then he realizes that the man holding his brother is that woman's husband.
Seems that Brigade was the type of man who would have been hunting Frank from the moment he knew it was he who killed his wife.