Opportunity makes the thief. Really? And so what?

This paper describes the work undertaken over many years by the author and colleagues concerning the role of opportunity in crime. The work began in the early 1970s in the Home Office Research Unit, the British government’s criminological research department. The work supported a preventive approach – situational crime prevention – that was highly contentious in the criminology of the day because it sought to reduce opportunities for crime, rather than to modify offender propensities. Critics claimed that situational crime prevention would displace rather than reduce crime because they assumed that opportunity merely determines the time and place of crime, but does not cause it. This paper describes the difficulties in establishing that opportunity is cause of crime and why this took so long. It reviews the research that was undertaken to this end, and it summarizes the benefits for criminology and crime policy of accepting that opportunity does cause crime.