Various journalists and scholars have described the now well-known “CSI effect.” Max Houck, director of forensic business development at West Virginia University, has said, “The CSI effect is basically the perception of the near-infallibility of forensic science in response to the TV show.” I would like to use this perception as a point of entry into the complex relationship between law and television. What is interesting about the CSI effect is not so much that television shows like CSI have altered public perception of the way the law does (or should) work, but that the step from the role of television spectator into the role of juror should seem so natural in the first place. Television has been altering audience expectations since its inception, but there is no “House effect,” no “ER effect,” no “Boston Public effect.” Why is it in the domain of the law that viewers feel implicated in – and drawn to comment on – the preservation of law's correct operation? The answer to this question comes in part from the fact of the jury system, which gives real individuals an actual active voice in determining legal outcomes. Most crimes, though, do not go to trial, and most jurors who serve do not end up on murder trials. The presence of the CSI effect has also to do with the ways in which law on television interpolates the viewer: at once as a singular witness, and also as a potential stand-in for a crucial enforcer.