Any such system is/would be potentially very dangerous. Crime data is not the same thing as crime. Populations that are over-policed are be disproportionately represented in any such data set, leading to higher prediction of crime, leading in turn more over-policing (feedback loop). I implore anyone attempting to build such a system to consider the serious issue of machine bias and it's implications in the real world.

See this tutorial given at this years NIPS machine learning conference: http://mrtz.org/nips17/#/