Explain the haverford case in which Atticus was involved

This refers to Atticus's first case in Maycomb. He took on the case of the Haverford brothers. The two men had killed a local blacksmith when that man had detained their horse. Not only did they kill him, they did so in front of three witnesses and then claimed that since the man had it coming, they shouldn't be in trouble. The brothers would not accept a plea deal thinking they were in the right. The were executed and Atticus hated criminal law from that point.