Kansas City Preventive Patrol experiment

The experiment began in October 1972 and continued through 1973; it was administered by the Kansas City Police Department and evaluated by the Police Foundation. It was designed to test the assumption that the presence (or potential presence) of police officers in marked cars reduced the likelihood of a crime being committed.
Patrols were varied within 15 police beats. Routine preventive patrol was eliminated in five beats, labeled "reactive" beats (meaning officers entered these areas only in response to calls from residents). Normal, routine patrol was maintained in five "control" beats. In five "proactive" beats, patrol was intensified by two to three times the norm.
The experiment asked the following questions:

• Would citizens notice changes in the level of police patrol?
• Would different levels of visible police patrol affect recorded crime or the outcome of victim surveys?
• Would citizen fear of crime and attendant behavior change as a result of differing patrol levels?
• Would their degree of satisfaction with police change?

Pause for a moment here. Whats your guess of what they found? Why do you think so?

OK. Here are the results

Did you expect this? Why/ why not?