Measuring crime: methods and approaches

Measuring Crime

During the latter half of the twentieth century, evidence-based policing became more commonplace, partly as a means to reduce corruption, but also as a means to make crime fighting more effective. Instruments used to measure crime at the federal level include those that fall under the rubric of the Department of Justice, such as Uniform Crime Reporting and National Crime Victimization Service. The FBI also operates legal attache offices, the Combined DNA Index System, and other tools used to measure and empirically track crime (Schmalleger, 2015, p. 147). Likewise, the Department of Justice maintains several major crime reporting programs including the National Incident-Based Reporting System. These reporting programs serve several core functions. They boost the effectiveness of criminal justice policy, they ensure policing and other aspects of criminal justice are evidence-based, and they inform the judicious allocation of resources throughout the criminal justice system. As Schmalleger (2015) points out, there are also instruments used to measure crime at the state and local level, as well as state and local level crime reporting programs. Some local jurisdictions like major metropolitan areas require their own means of data gathering and analysis.

Crime rates refer to the number of reported offences in a specific crime category within the population. The Uniform Crime Reporting service of the Department of Justice accounts for three different crime rates: offense rates, arrest rates, and clearance rates. For the most part, the UCR crime rates focus on street crimes as opposed to white collar crimes. Offence rates are typically expressed by number of offences in the particular category per every 100,000 people. In areas with fewer than 100,000 people, the number of residents is divided by 100,000, then the number of reported crimes is then divisible by the result of that number.

Arrest rates draw data from individual jurisdictions, within the past twelve months. Just because a crime has been reported does not mean that a suspect was found and arrest made, which is why arrest rates point more to the effectiveness of the police in locating suspects and making arrests. Unfortunately, arrest rates can be artificially increased through aggressive policing in an attempt to make a specific department appear to be doing a good job (Silver, 2014). A range of other factors can artifically influence rates of arrest, including the use of racial profiling (Schmellager, 2015).

Clearance rates take into account the number of times charges have been filed or "cleared" through the system. Thus, both crime rates and arrest rates can be used to determine a composite percentage used to determine the effectiveness of a given policy. Clearance rates can also determine net changes in overall crime rates. Recidivism rates are something different altogether, as this data refers to the number of repeat arrests. However, rates of recidivism likewise provide insight into the effectiveness of local policing efforts and criminal justice policies.

According to the Myth v. Reality: Crime Has Been Steadily Increasing video, rates of crime, like any other statistic, can be deceiving. Rates of crime do not offer any information about victimization. Moreover, crime rates are based on official reports and not on actual instances, many of which may go unreported. It can be difficult to determine causality when rates of crime increase or decrease. Moreover, arrest rates tell a different story from crime rates. Arrest rates can be related as much to police department policy or to shifts in the normative culture of the community. Likewise, the decision on whether or not to press charges is often left up to the police or prosecutor. Police and prosecutorial discretion can impact clearance rates. As Myth v. Reality points out, crime rates can also mislead the public into thinking that their neighborhood, community, or society is safer -- or less safe -- than it actually is. Some types of crimes are reported more than others, data is collected on some crimes but not on others, and the types of crimes that the media focuses on such as murder, rape, and armed robbery are not the most costly to society (Myth V. Reality). Another drawback with crime rate statistics is that reporting may be racially biased; the race of the victim may have a bearing on whether the crime is reported, whether an arrest is made, and whether the crime has been cleared by law enforcement.