It is difficult to determine the amount of crime that occurs in our communities every year, because many crimes never come to the attention of the criminal justice system. There are various reasons that will be discussed, such as victims fearful of reporting, victims not realizing they are victims, and offenders not getting caught. Although 2020 was an exceptional year in many ways, research by the Bureau of Justice Statistics shows that just 40% of violent crime, and 33% of property crimes, were reported by victims to the police that year.  Because of this severe underreporting of crime, criminologists often refer to a concept known as the dark figure of crime.
There are three general sources of crime statistics that will be covered in this chapter: official statistics, which we often describe as reported statistics, self-report statistics, and victimization statistics. Each of these sources of crime statistics has pros and cons, and we will spend time discussing those as well. Additionally, we will discuss the importance of looking at crime trends over time, relying upon statistics and research when developing policy, and how data should be a tool that enhances the criminal justice system.
If we have accurate and reliable crime statistics, we can evaluate criminal justice policies and programs. For example, we could use crime statistics to see if mandatory minimum sentences for drug offenders reduce recidivism, or whether the elimination of cash bail (for pre-trial release) is related to increases in crime in a particular place. (Of course, these are complex research questions with equally nuanced answers. Read here if you’re interested in the question of mandatory minimums!)
As we’ve already seen, relying on official statistics can be problematic, because many crimes never even come to the attention of the criminal justice system. Official statistics only reflect crimes that are known or reported to the police by victims. It may seem shocking that people do not report crimes, but it is more common than we think. Let us take the example of looking at the gap between reported and unreported crimes.
Dark Figure of Crime Example
When I lived in New York City, a friend of mine was sexually assaulted by a stranger who followed her into her building. When she phoned the police to make a report, they told her that they would have to come to her apartment to take the report in-person, a process that they explained could take “hours.” Not surprisingly my friend felt like her report would be a burden for both herself and the police, and ultimately, she decided not to make the report. When she was assaulted for a second time under similar circumstances, she did not phone the police at all.
I can remember another example of non-reporting from my childhood. One day upon arriving home, my father and I discovered that our apartment had been burglarized. Roughly $50, a guitar, and some camera equipment had been stolen. My father felt confident that his friend (who was currently struggling with an illicit substance use disorder) had broken in and taken his stuff to sell. While the financial loss was significant for him, he decided not to report, since he didn’t want to get his friend arrested, and had little hope of recovering his stolen property.
As we can see from just these two anecdotes, there are many and complex reasons why people do not report (even serious) crime. When victims of crime do not report, or police are not made aware of a crime, these crimes go uncounted in the official statistics. They become part of the ‘dark figure of crime‘ that we will learn about throughout this section. 
- https://bjs.ojp.gov/press-release/criminal-victimization-2020 ↵
- Biderman, A., & Reiss, A. (1967). On exploring the "dark figure of crime." The Annals of the American Academy of Political and Social Science. 374(1), 1–15. https://doi.org/10.1177/000271626737400102 ↵
- Brantingham, P., & Brantingham, P. (1984). Patterns in Crime, New York: Macmillan. ↵