What were brown's motives for committing a crime?

Brown justified his motive for the murder if Clarkson, as the physical harassment of his daughter by Clarkson, who was married to Brown's ex-wife. Brown insisted that Clarkson was harassing his step-daughter (Brown's daughter), and to prevent her, Brown shot Clarkson. However, he failed to produce any evidence to prove so and w a s given death sentence.