The crime triangle (also known as the problem analysis triangle) comes striaght out of one of the main theories of environmental criminology - routine activity theory.
“Routine Activity Theory” provides a simple and powerful insight into the causes of crime problems. At its heart is the idea that in the absence of effective controls, offenders will prey upon attractive targets. To have a crime, a motivated offender must come to the same place as an attractive target. For property crimes the target is a thing or an object. For personal crimes the target is a person. If an attractive target is never in the same place as a motivate offender, the target will not be taken, damaged, or assaulted. Also, there are controllers whose presence can prevent crime. If the controllers are absent, or present but powerlessness, crime is possible.
First, consider people who are influential in the lives of potential offenders. In the case of juveniles these might be parents, close relatives, siblings, peers, teachers, coaches, and other similarly placed individuals. In the case of adults these people may include intimate partners, close friends, relatives, and sometimes their children. These people are called “handlers” in routine activity theory. Crimes will take place where handlers are absent, weak, or corrupt.
Next consider targets, or victims. Guardians try to protect targets from theft and damage and potential victims from attack and assault. Formal guardians include the police, security guards, and others whose job is to protect people and property from crime. Informal guardians include neighbors, friends, and others who happen to be in the same place as the attractive target. Parents, teachers, peers and others close to potential victims are also potential guardians. A target with an effective guardian is less likely to be attacked by a potential offender than a target without a guardian. If the guardian is absent, weak, or corrupt little protection is provided the target.
Finally, consider places. Someone owns every location and ownership confers certain rights to regulate access to the site and behaviors of people using the site. The owner and the agents of the owner (e.g., employees) look after the place and the people using the place. Owners and their agents are called place managers. Place managers control the behavior of offenders and potential victims. Examples of place manager include merchants, lifeguards, parking lot attendants, recreation and park workers, janitors, and motel clerks. In the presence of an effective place manager, crime is less likely than when the manager is absent, weak or corrupt.
All of the people in this theory use tools to help accomplish their criminal or crime control objectives. Tools that gang members use may include spray paint cans, guns, and cars. Offenders without access to tools are less likely to be able escape handlers, enter unauthorized places, and overcome victims, guardians, and managers. Guardians may use light to increase surveillance, engraving devices to mark property, and other devices to help reduce the chances of victimization. Place managers can use gates, fences, signs and other tools to regulate conduct. With effective tools handlers, victims, guardians, and managers will have a greater chance of keeping crimes from occurring. The tools used are often highly specific to the crime in question. The tools an offender needs for a burglary (e.g., a screw driver) are likely to be different from those needed for a robbery (e.g., a gun), for example.
The relationship of the actors, places and tools is depicted in the problem triangle, shown in Figure 1. Problems occur when offenders are at the same places as targets, without any effective controller. If one or more of the controllers is present, however, the chances of crime are greatly reduced. The effectiveness of the people involved will depend, in part on the tools they have available. Adding or subtracting various elements in this model will alter the chances of crime.
The presence of attractive targets, weak handlers, ineffective guardianship, and indifferent management is not randomly distributed across places. Offenders do not wander aimlessly across the landscape. Like everyone else, offenders have routine behaviors that take them away from handlers and lead them to discover places with attractive targets. Potential victims also follow routines that separate them from effective guardians in places with weak management. The spatial ordering of crime opportunities and the routines of offenders and victims creates many of the crime problems we see.
This theory of crime also suggests ways of preventing these problems. The questions in the guide and the responses list are organized around each of the eleven elements shown in Figure 1. The guide asks problem solvers a series of questions about offenders, handlers, targets, guardians, places, managers, and the tools used by each. The answers to these questions, which will vary by problem, suggest possible responses. Thus, responses are problem specific (for example, a residential burglary problem in a neighborhood of single family residences may require different responses than one in a large apartment complex, and a residential burglary problem in an apartment complex near a heavily traveled highway may require different responses than one in an apartment in a more isolated location).
Though responses are problem specific, there are often several possible responses to any specific problem. Few problems will have unique responses. Instead, the special insight of problem solvers is to choose among possible responses that can be implemented. Further, if one approach does not work, other backup responses are usually possible.
Though it is possible to use the guide and responses list without understanding the basics of routine activity theory, knowing this theory helps use the guide and list with greater flexibility. For example, if someone proposes a potential solution to a problem, it is possible to determine if the solution is appropriate. To do this the problem solver identifies which of the 58 possible responses the proposed solution resembles most closely. The problem solver then works backwards from the solution list to the questions. The questions describe the types of answers needed for the solution to fit the problem. If the answers to the questions are consistent with the solution, the proposed solution may be appropriate. In short, the more familiar one is with routine activity theory, the more adaptable the guide and solution list will be. Additional information on routine activity theory can be found in the references cited below, particularly Clarke (1997) and Felson (1994).
Brantingham, Patricia L. and Paul J. Brantingham (1981). “Notes on the Geometry of Crime.” In Environmental Criminology, edited by Paul J. Brantingham and Patricia L. Brantingham. Beverly Hills: Sage.
Clarke, Ronald V. (1997). Situational Crime Prevention: Successful Case Studies. Second edition. Albany, NY: Harrow and Heston.
Cohen, Lawrence E. and Marcus Felson (1979). “Social Change and Crime Rate Trends: A Routine Activity Approach.” American Sociological Review. 44:588-605.
Eck, John E. (1994). Drug Markets and Drug Places: A Case-Control Study of the Spatial Structure of Illicit Drug Dealing. Unpublished Ph.D. dissertation, University of Maryland, College Park.
Felson, Marcus (1994). Crime and Everyday Life: Insight and Implications for Society. Thousand Oaks, CA: Pine Forge Press.
Note that people can fill multiple roles. A father example, can be a handler of a teenager when he prevents his son from accompanying his friends on a drinking spree. He can be a guardian when he accompanies his son in risky circumstances. And he can be a manager when he prohibits his son from having a keg party in his home.