William Brock told investigators he shot Loletha Hall because he thought she was working with a man who called and threatened him and his family. Hall did not threaten Brock and did not have a weapon or assault him, according to the sheriff’s office and court documents.
Because it was set many decades ago and never adjusted for inflation.
(I haven’t bothered to check if that’s true for this specific case, but it’s a pervasive problem throughout the US legal code so I’m hazarding a guess.)