Lines Drawn in Battle Between Free Will and Determinism

NPR has a philosophically fascinating special series called "Inside the Criminal Brain."  The whole series is worth a look, but I want to focus on a specific case:

"When the police arrived at Bradley Waldroup's trailer home in the mountains of Tennessee, they found a war zone. There was blood on the walls, blood on the carpet, blood on the truck outside, even blood on the Bible that Waldroup had been reading before all hell broke loose.

"Assistant District Attorney Drew Robinson says that on Oct. 16, 2006, Waldroup was waiting for his estranged wife to arrive with their four kids for the weekend. He had been drinking, and when his wife said she was leaving with her friend, Leslie Bradshaw, they began to fight. Soon, Waldroup had shot Bradshaw eight times and sliced her head open with a sharp object. When Waldroup was finished with her, he chased after his wife, Penny, with a machete, chopping off her finger and cutting her over and over."

So what makes this gruesome murder a front line in the battle between free will and determinism?  Join me below the fold...