The use of “algorithms” in criminal investigation, adjudication, and punishment is not a new phenomenon. That is, to the extent that “algorithms” are simply sets of rules capable of being executed by a machine, the criminal justice system has long incorporated their use. For example, the US sentencing guidelines are so mechanistic that they were, at least for a time, literally calculated by software. Likewise, the New York Police Department’s erstwhile “stop and frisk” program was a mechanistic means of deciding whom to search and when. And so-called “per se” impaired driving laws have for nearly half a century mechanistically imposed criminal liability based on a machine’s determination that a person’s blood-alcohol level is over a certain threshold, without a jury determination of dangerous impairment.