Second of four parts

In the fall of 2007, Davie County prosecutors studied a suspicious bloodstain in a crime scene photograph, looking for evidence that Kirk Turner intentionally slashed his wife's throat with a pocketknife.

Turner, a Kernersville dentist, said he killed Jennifer Turner in self-defense after she attacked him with a 7-foot spear. But prosecutors noticed a V-shaped stain on Kirk Turner's T-shirt.