How can science help at a crime scene? What is circumstantial evidence and how can science prove or disprove it? How do police databases work? Discover how scientists are fighting back against the threat of crime, from murder to theft, and explore the incredible weapons they are wielding to do so. The book looks at crime scene evidence, from fingerprints to DNA samples, and explains why these leave the police and scientists important clues. It then explores how the police use this science, along with technology such as CCTV and crime databases, to track down the criminals.