Remember that Tom Cruise movie Minority Report, from the Philip K. Dick book? Set in the future, the police caught all potential wrongdoers before they committed their crime(s), which was made possible by the ability of some special people to know about crimes individuals were planning to commit. In the same film, I also enjoyed the little crime-fighting robots that were sent into people's apartments to scan the occupants' eyeballs for identification. For those that haven't seen the film, I won't spoil it by revealing the ending.