The number of home burglaries is growing, and the clear-up rate is low because crime analyses are usually elaborate and tedious. PRECOBS (Pre Crime Observation System) provides a solution to the problem. In just a few minutes, the software sifts through all the criminal data and predicts where and when the next burglary will occur. The idea behind the system: criminals act according to patterns that enable predictions to be made about subsequent crimes. And then the police can be at the crime scene before the criminal, and apprehend him before anything happens. The method has proved successful. In the regions in which PRECOBS has been used so far, crimes have decreased by 30 per cent.