Katie Clover had been dead for twenty-five years, and there had been DNA carrying her killer's profile since the second week of the investigation, skin cells recovered from under her fingernails, fetal DNA from a pregnancy nobody, not even her best friend, had known about until the autopsy. Run it through every database available back in the summer of 2000 and you got nothing, no match, no name, just a lab folder that got thinner every year while a promising eighteen-year-old runner from S...