"Expensive locks didn't help me when my office was robbed a few weeks ago, in broad daylight. The thief who made off with the computers was identified and caught through the vigilance of someone in my building who noted a suspicious character lurking about.
This experience points to the importance of natural surveillance for crime prevention, one of the principles of CPTED (Crime Prevention Through Environmental Design). CPTED, an approach that originated in the 1960s, is based on a theory that the proper design and effective use of the built environment can reduce crime and the fear of crime.
Research into criminal behaviour shows the decision to commit a crime or not is heavily influenced by cues about perceived risk of being caught. CPTED strategies increase a criminal's perceived risk of detection using three main strategies: Natural surveillance, natural access control and natural territorial reinforcement."