A study conducted by scientists from the University of Virginia Health System shows that there is a relation between green space and violent crime:
How green space can reduce violent crime (source: ScienceDaily)
Summary: if green spaces in a neighborhood are well designed and maintained crime rates will be lower, while if the opposite is true crime rates will be higher. Also well-designed public green keep people healthier.
This of great importance for any society that is devoted to the prevention of crime – rather than to rely upon repression. Urban planning and design should take crime prevention into account in order to achieve a low crime society.