Part V — Digital and Emerging Forensics

The newest evidence, and the newest claims. For most of forensic history the evidence was physical — a print, a fiber, a body. Today the most important witness in a great many cases is a device: a phone that logs where its owner went and what they typed, a hard drive that remembers what was deleted, a camera that recorded what no person saw. Part V covers this new terrain, and it covers it with the same yardstick as everything else, because new is not the same as valid. Some of what is here is rigorous and grounded in mathematics — a cryptographic hash either matches or it does not. Some of it — "enhance that image," the television profiler who reads a killer's soul from a crime scene — is as oversold as anything in the book. The job is to tell them apart before they enter a courtroom.

The arc runs from the most established digital discipline to the most speculative. We begin with digital forensics proper — imaging, hashing, the evidence you can't delete — then move to the reading and authenticating of images and video in an age of deepfakes. From there to the money, where forensic accounting follows the paper trail that often outlives every other kind of evidence; to the mind, where forensic psychology and the much-hyped business of profiling get an honest and deflating audit; and finally to the technologies just now entering the field, held to the same standard as the oldest. In this part, the Cold Case's alibi breaks.

  • Chapter 25 — Digital Forensics: Computers, Phones, and the Evidence You Can't Delete establishes integrity by mathematics — forensic imaging and hash values — and shows where evidence hides in metadata, deleted files, and cell-site data.
  • Chapter 26 — Video and Image Forensics: Enhancement, Authentication, and Deepfake Detection tells the truth about "enhancement," teaches authentication and provenance, and confronts synthetic media.
  • Chapter 27 — Forensic Accounting: Following the Money traces fraud, motive, and the audit trail, with Benford's law and anomaly detection — and uncovers the Cold Case's financial motive.
  • Chapter 28 — Forensic Psychology and Criminal Profiling: What Works (Not Much) and What Doesn't separates the real, careful work of competency and risk assessment from the over-sold television profiler, and asks honestly whether profiling works.
  • Chapter 29 — Emerging Technologies: AI in Forensics, Rapid DNA, Microbial Forensics, and the Future holds rapid DNA, microbial forensics, isotope analysis, and machine learning to the same validity yardstick before they become courtroom certainties.

Part V advances two themes most strongly. The first is the CSI effect cuts both ways, in its purest form: nowhere does television lie more than here — the instant "enhance," the omniscient profiler, the AI that names a suspect — and Chapters 26 and 28 exist largely to deflate those fictions and replace them with what the methods can honestly do. The second is not all forensic methods are equally valid, applied to the future tense: Chapter 29 insists that a method's novelty is no substitute for its validation, and that the next generation of forensic tools must clear the same bar — a measured ability to do what they claim, with a known error rate — that DNA cleared and bite marks never did.

Chapters in This Part