The Horizontal Gaze Nystagmus test: fraudulent science in the American courts

The Horizontal Gaze Nystagmus (HGN) test was conceived, developed and promulgated as a simple procedure for the determination of the blood alcohol concentration of drivers suspected of driving while intoxicated (DWI). Bypassing the usual scientific review process and touted through the good offices of the federal agency responsible for traffic safety, it was rushed into use as a law enforcement procedure, and was soon adopted and protected from scientific criticism by courts throughout the United States. In fact, research findings, training manuals and other relevant documents were often held as secrets by the state. Still, the protective certification of its practitioners and the immunity afforded by judicial notice failed to silence all the critics of this deeply flawed procedure. Responding to criticism, the sponsors of the test traveled the path documented in this paper that led from mere (if that word can ever truly apply to a matter of such gravity) carelessness in research through self-serving puffery and finally into deliberate fraud--always at the expense of the citizen accused.