The collection of electronic crime data allows law enforcement agencies to map each instance of crime digitally. By plotting crimes on a map, along with data about demographics, businesses, institutions, and known offenders, crime analysts using GIS have created an entire subfield of geography known as forensic geography or crime mapping. GIS, in the hands of crime geographers, offers law enforcement agencies a robust analytical toolkit that can offer both long-term policy guidance and short-term tactical advice.
Numerous television shows feature crime analysts who engage in criminal profiling, which is a kind of pseudo-scientific attempt to identify perpetrators of crime based on psychological characteristics and behaviors of suspects. Geographers use more scientifically rigorous analyses of data to identify likely suspects in specific types of crime sprees. Perhaps the most thrilling application of spatial principles in the study of crime is known as geographic profiling, a collection of techniques designed to identify spatial patterns in criminal behavior. Serial offenses, like arson, murder, car theft, etc. can be mapped, and by observing the criminal tendencies (modus operandi or M.O.) of offenders, analysts attempt to predict where an offender is likely to commit additional crimes, and even where the offender may live. Criminal activity, like most other activity, is conditioned by the principle of distance decay, therefore it can be assumed that most criminals tend to commit crimes near their home, or another locus of activity. With crime, however, there is a caveat: most serial criminals tend not to commit a crime in very close proximity to their home/workplace because they fear that someone would recognize them at/near the crime scene.
There are significant variations in the spatial pattern of crime sprees that depend on the individual serial criminal, the type of crime, and the geographic peculiarities of the region; but in some instances, criminals behave just as the geographers’ theories suggest and analysts using GIS can occasionally make predictions with reasonable accuracy. An assignment accompanying this text allows students to do some geographic profiling with data associated with crimes committed by the so-called Hollywood Arsonist, who set nearly 60 fires during several days near New Year’s Day 2012. Far more complex procedures are available to advanced students of the craft, including Rossmo’s Formula. More Americans are becoming aware of the power of GIS thanks to the publicity generated by television crime dramas (like NCIS, CSI, or Numb3rs) that occasionally feature geeky GIS crime analysts helping detectives solve baffling crime sprees.
Figure 8-9: Hollywood, CA – A serial arsonist burned nearly 60 buildings during the New Year's holiday 2011-12. Basic statistical techniques indicated where the perpetrator was likely to live. Data Source: LA Times
Social Disorganization Theory
Most geographers who study crime focus not on the behaviors of individuals, but rather on groups and the contexts in which they live, as a way of understanding crime trends. Criminal behavior exhibits trends at the neighborhood, county, state, and national levels permitting an array of research possibilities. By mapping crime data along with a variety of social, cultural, economic and law enforcement data, crime analysts not only can begin to understand why crime happens where it does, but they can also assist in making neighborhoods safer by helping officials redirect scarce resources to locations where they are most needed. New York City’s Police Department has employed a GIS-based, quality of life/crime data management tool called CompStat for years with celebrated success.
The most popular theory guiding research into the geography of crime is known as Social Disorganization Theory. This theory was built upon observations made by researchers from the so-called Chicago School who began using maps to understand crime over 100 years ago. According to this theory, place really matters. In other words, Social Disorganization Theory posits that neighborhoods create conditions that may encourage or discourage criminal behavior. Of course, individuals within any neighborhood may choose to pursue or avoid criminal activity, but numerous studies have shown that criminal behavior is far more common among people from areas that fit certain demographic and economic profiles.
What factors predict an elevated crime rate? Poverty, ethnic heterogeneity, and residential mobility are the chief indicators, and they manifest themselves in ways that are relatively easy to measure. According to this theory, poor neighborhoods, with a heterogeneous population, where people frequently move in and move out, residents are unable to exert effective,collective social control. This is like a family where parents have lost control of their children because they don’t know them well enough, and have little leverage over them. In neighborhoods, where the population is wealthier, stable, and homogenous people tend to develop a shared sense of right and wrong, and they become more willing to defend their neighborhood (and property values) from those who would commit crimes. You are far less likely to “defend your neighborhood” when you don’t know your neighbors, and you don’t have a sense of ownership over your neighborhood.
One of the more important findings made by the chief architects of this theory many years ago was that ethnicity was not directly related to crime. They came to this conclusion by mapping different ethnic groups as they moved up the socio-economic ladder and from neighborhood to neighborhood. What Shaw and McKay found was that recent immigrant groups often exhibited high rates of juvenile delinquency while they lived in a specific type of neighborhood. Yet when those immigrant families moved into more stable and prosperous neighborhoods, the delinquency rate of juveniles declined. For those families from the same ethnicity that remained in the old neighborhood, the delinquency rate did not decline. Therefore, ethnicity could not be at fault. Instead, it was the cultural ecology (or social environment) of the neighborhood that made a difference. Geography matters.
This text’s author used these very same theories to co-author a study analyzing the effect of payday lenders on crime rates in Seattle, Washington. By using social disorganization theory to conduct a GIS-based statistical analysis, it was possible to forcefully argue that 1) neighborhood variables like the of percent young males, the jobless rate, the residential instability of residents, the population density, etc.strongly predicted crime rates; 2) when those factors were held statistically constant, the addition of specific businesses or institutions (in this case payday lenders), crime rates worsened significantly over time. Similar studies have analyzed the effect of a variety of landscape elements on crime, including parks, liquor stores, and schools. Most have found that neighborhood variables affect the propensity of residents to engage in criminal behaviors.
Modeling Crime
Consider a situation in which a person has petitioned your local government for a license to open a liquor store (or casino, flower shop, or gymnasium) in your neighborhood. City officials and concerned residents may want to estimate the effect such an establishment might have on local crime rates. A geographic approach would call for an analysis of similar instances occurring in the past, or in other locations, perhaps in other towns or in other parts of the same city. A common technique used by geographers is to first map the relative data and then create a regression model of the variables. Regression models are statistical tests that allow users to estimate the effect of one or more causal variables (e.g., income, education, liquor stores, etc.) have on an outcome variable (e.g., crime rates). Modeling crime with regression models is a well-established technique among social scientists. It not only permits analysts to identify likely causes of criminal activity but also by mapping the results of the test, geographers can identify neighborhoods that have crime rates that are higher/lower than what is expected, based on predictions made by the regression model. Law enforcement officials can use these maps to decide where to deploy additional resources, or to investigate more closely the factors contributing to higher (or lower) than expected crime rates in a specific location.
Hot Spot Analysis
Patterns of criminal behavior that might be impossible to spot in a spreadsheet or among stacks of crime reports are often readily discernible using GIS. One pattern mapping technique is called hotspot analysis. One version of this technique begins with a simple point map of crimes, but the GIS software calculates small buffer zones around each point. Those areas with multiple overlapping buffers are assigned a progressively higher score on a color-coded pixel grid map, thereby enabling GIS users to quickly visualize the presence (or absence) of multiple crimes in the region. Hotspot maps may also indicate the location of a nexus of criminal activity (like a drug dealer) even when no arrests have been made at a location. GIS analysts can also add to a hotspot map addresses of known felons, repeat offenders, parolees or institutions, like pawn shops, liquor stores or strip clubs to help identify likely suspects, or landscape elements affecting crime.
Figure 8-10: Los Angeles, CA – This hot spot map of car thefts in the eastern San Fernando Valley shows that cars theft is worst in high traffic areas, along commercial corridors. Data Source: City of Los Angeles
Broken Windows Theory
A crime theory advanced by Wilson and Kelling in the 1980s argued that the appearance of neighborhoods was another factor in the pattern of crime in cities. This idea, known as Broken Windows Theory, suggests that visual indicators of disorder on the landscape (e.g., trash, graffiti, vandalism) signal to passers-by that there is a low level of social control and community investment in an area. In other words, where visual disorder is evident, people assume that behavioral disorder is also acceptable. At the very least, visual disorder is a signal to would-be criminals that if even if residents do not approve of criminal behaviors, there is likely to be little consequence for those who commit crimes. On the other hand, in places where it’s obvious that people are caring for their windows, lawns, walls, streets, and sidewalks, criminals will surmise that residents actively monitor the behavior of others, and are likely to act against those who violate the social norms associated with well-kept locations.
Figure 8-11: Detroit, MI - The abandoned Michigan Central rail station near downtown Detroit signals to all that this neighborhood has little social or government authority.
Implications of this theory suggest that police and residents should vigilantly guard against visual disorder. Windows that are broken should be fixed immediately. Graffiti should be painted over immediately, trash should be removed quickly, and repairs to buildings should be made as quickly as possible. Lawns should be mowed and kept tidy, etc.
Zero Tolerance Policing
Many police departments across the United States embraced the principles of Broken Windows Theory in the 1990s and attempted to apply the logic to a crime prevention strategy known as Zero-Tolerance Policing, a misapplication of Broken Windows Theory that has generated intense controversy. Zero Tolerance Policing incorrectly assumed that disorderly behaviors by citizens had the same effect on crime as visual disorder on the landscape. By assuming that allowing small transgressions of the social order and/or petty crimes to go unpunished signaled to citizens that serious crime must also be OK, police departments embracing this thinking began cracking down on all sorts of small crimes. The idea behind Zero Tolerance Policing is that by arresting people for small crimes (graffiti, petty theft, failing to pay subway fares, etc.) people will not engage in major crimes. Zero-Tolerance Policing policies give officers little discretion in the sorts of crimes they actively pursue. Every little crime must be stopped. Arrests for petty crimes must be made. In New York City, Zero Tolerance Policing evolved into a strategy known as Stop and Frisk. Under this policy, the number of times New York City cops stopped and questioned individuals on the street quadrupled went from less than 100,000 in 2002 to over almost 700,000 in 2012.
Figure 8-12: Chillicothe, OH - This town, after witnessing a spike in opioid related crime, adopted a stop-and-frisk policy like New York City's.
Black and Latinos were disproportionately targeted for police stops and interrogations, leading to protests and lawsuits accusing police of illegal racial profiling. The Black Lives Matter movement is in some ways a reaction to the misapplication of Broken Windows Theory.
Figure 8-13: New York, NY - Protestors march to protest "Stop and Frisk" policing. People of color often view the strategy as racial profiling. Source: Wikimedia.
Advocates of Stop and Frisk policies have pointed to the dramatic reduction in crime in New York City since the adoption of Zero-Tolerance Policing there. Critics counter-claim that other cities, including most that do not use zero-tolerance policing, have experienced similar dramatic reductions in crime rates. Other research suggests that attending to visual blight in neighborhoods, such as graffiti, garbage, broken streetlights, etc., resulted in a similarly positive reduction of crime rates, without widespread complaints from communities of color about police harassment.
In 2020, after what appeared to be some improvement in relations between police and communities of color, widespread protest erupted once again in the wake of a series of high-profile tragedies involving police and black citizens in the US. Unlike earlier protests that were largely confined to major cities with large minority populations, the 2020 spring protests were staged in small towns, white suburbs and even spread to Europe, where protestors expressed solidarity with both American people of color and European minority populations that have in recent years suffered increased racism, anti-immigrant hostility, and xenophobia. Calls for significant changes in the American criminal justice and policing policies seemed to gather momentum, under the unfortunate slogan “Defund the Police”.
Figure 8-14: Ottawa, Canada: Protestors call for a reconsideration of policing policies and how police departments are funded. Source: Wikimedia
