The serial killer has a special place in crime fiction and true crime. Blame Jack the Ripper and his acolytes—without him, the category would not have such a neat lineage. The serial killer is an optimal foe in as much as he is completely amoral and usually preternaturally intelligent. Some are handsome and charismatic, like Ted Bundy, who used his good looks and charm to lure his victims. Others live off the grid, like the Unabomber. In fiction, the serial killer is a tempting trope because if the story slows...