I Know Who You Are
How an Amateur DNA Sleuth Unmasked the Golden State Killer and Changed Crime Fighting Forever
“A true-crime masterpiece written by a cold-case-cracking master. Barbara Rae-Venter’s investigative DNA work has revolutionized the way law enforcement hunts serial killers.”—John Douglas, New York Times bestselling co-author of Mindhunter
“Barbara Rae-Venter isn’t just the genealogy expert who helped capture the Golden State Killer—she’s an unsung hero who has given murdered women and children their faces and names back, recognizing that their lives mattered.”—Maureen Callahan, New York Times bestselling author of American Predator
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 I Know Who You Are, 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. From the first criminal case she ever solved—uncovering the long-lost identity of a child abductee—to the heartbreaking story of the Billboard Boy, whose skeletal remains were discovered along a highway, to the search for the Golden State Killer, Rae-Venter shares haunting, often thrilling accounts of how she helped solve some of America’s most chilling cold cases in the span of just three years.
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. Readers join in on urgent calls with sheriffs, FBI agents, and district attorneys as she details the struggle to obtain usable crime scene DNA samples, until, finally, a critical piece of the puzzle tumbles into place.
I Know Who You Are captures both the exhilaration of the moment of discovery and the sheer depth of emotion that lingers around cold cases, informing Rae-Venter’s careful approach to her work. It is a story of relentless curiosity, of constant invention and reinvention, and of human beings striving to answer the most elemental questions about themselves: What defines identity? Where do we belong? And are we truly who we think we are?
Investigative genetic genealogist Rae-Venter debuts with a remarkable account of how law-enforcement tapped into her use of DNA matches "to build family trees and help solve unknown parentage issues." Upon retirement from her career as a patent attorney, Rae-Venter dove into researching her family tree, using DNA tests to identify relatives. In 2015, the San Bernardino County Sheriff's Department sought her help identifying the real identity of a 30-something woman, Lisa Jensen, who was abducted as a young child. Rae-Venter's use of Jensen's DNA enabled her to establish Jensen's real name, and in another case identify a serial killer. These successes paved the way for her involvement in the Golden State Killer case; her dogged research revealed ex-cop Joseph James DeAngelo Jr. to be the person responsible for dozens of rapes and murders in California during the 1970s and '80s, crimes for which he pleaded guilty in 2020. Rae-Venter makes the science accessible and delves into the controversy that forensic genealogy has engendered because of privacy concerns. She is less bothered by those qualms, believing fears of a dystopian future stemming from law-enforcement use of genetic information are overwrought. It's an eye-opening and thought-provoking contribution to the true crime genre. Agent: Frank Weimann, Folio Literary Management.