Six - Visibility / Surveillance
This principle is defined as "Making sure that offenders would be visible if they carried out a crime." Unlike any of the other principles, there are three types of surveillance, these are:
Natural
Formal
Informal.
Like all the other principles there is a range of methods and techniques that can be applied.
Natural surveillance
Involves modifying the existing surroundings to increase visibility. It can include:
pruning or removing shrubbery
improving or installing lighting
changing the height of fences
placing a playground area so that it overlooks nearby homes (and is overlooked by those homes).