How trustworthy is fingerprinting? How do insects help determine the time of a kill? How are political and war criminals found in portraits made with aging in mind? In this book, the world-famous Scottish writer, author of detective stories Val McDermid changes roles and undertakes her own investigation. Its heroes are detective geniuses and ordinary policemen, great scientists and painstaking experts. High-profile cases that became the basis for movie plots, serial killers, victims of unhappy love or extreme sexual games, arsonists, molesters, scammers, marriage swindlers . . . And the search for truth. Before us unfolds a long history of forensic science - from the forensic science of ancient China to DNA profiling - with its mistakes and victories, when, after many years, it is possible to find a criminal and give freedom to an innocent convict.