For twelve years the Golden State Killer terrorized California, stalking victims and killing without remorse. Then he simply disappeared, for the next forty-four years, until an amateur DNA sleuth opened her laptop. In this book, Barbara Rae-Venter reveals how she went from researching her family history as a retiree to hunting for a notorious serial killer-and how she became the nation's leading authority on investigative genetic genealogy, the most dazzling new crime-fighting weapon to appear in decades. Rae-Venter leads readers on a vivid journey through the many cases she tackled, often starting with little more than a DNA sample. For each investigation, Rae-Venter brings readers inside her unique "grasshopper mind" as she analyzes DNA data and pores through obituaries, marriage records, and old newspaper articles.