Statistical Methods and Models

Statistics play an important role in criminal justice research and policy making. Every day, the public is exposed to a vast amount of information regarding crime and criminal justice. This information commonly takes the form of news reports, political speeches and campaigns, public opinion surveys on issues like the death penalty or drug legalization, and debates with friends and family members about crime-related issues. The majority of the information presented in these contexts is based on numbers (i.e., statistics), such as crime rates, arrests made by the police, number of people in prison, length of prison sentences, or victimization rates.

The use of statistics allows us to collect a large amount of quantitative data, organize it, and search for trends that may help explain what is going on in the world around us. For example, the Federal Bureau of Investigation's (FBI) Behavioral Science Unit is responsible for creating psychological and criminal profiles of serial killers to aid in the investigation of new and unsolved cases. These profiles are based upon the statistical analysis of information collected from hundreds of crime scenes, interviews of offenders and victims, and psychological studies. In creating these profiles, the Behavioral Science Unit uses various statistical models to determine common characteristics across different types of serial killers. They are able to do this because [Page 1572]similar types of serial killers tend to select similar victims, use similar methods in committing their crimes, and often have similar personal backgrounds.

Criminology and criminal justice issues tend to be extremely controversial, with most people forming opinions from personal experiences or from hearing about someone else's experiences. Statistics, however, allow researchers to make objective interpretations of numeric information. To make sound decisions, all criminal justice professionals, including police chiefs, prison and jail administrators, and judges, use statistical methods to more fully understand important issues rather than rely solely on personal opinion or experience. For instance, in the late 1970s, criminal justice officials and politicians were excited about a new program that many believed would stop delinquents from becoming serious criminals. This program, called Scared Straight, placed small groups of teenagers into maximum security prisons where inmates, usually serving life terms, graphically described the brutality and horror of prison life. The purpose of the program was to scare the delinquents away from a criminal path. This program was so popular that it was broadcast nationally and received Oscar and Emmy awards. However, evaluations of the Scared Straight program using statistical models found that the program actually had the opposite effect: youth attending the Scared Straight program were more likely to commit crime than similar youth who did not attend the program. These statistical findings led to a major restructuring of the program.