Compare and contrast Arthur Lux and Vinny Pearson from the novel, In the Lake of the Woods?

Arthur Lux and Vinny Pearson are both cops, and they both show up to investigate Kathy's disappearance. Arthur Lux thinks highly of John, and is sympathetic to his loss, but Vinny Pearson is determined to prove that John killed Kathy, and does not hide his contempt.