It is difficult to determine that 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 not reporting, victims not realizing they are victims, and offenders not getting caught. Research reveals, that on average, more than half of the nation’s violent crimes, or nearly 3.4 million violent victimizations per year, went unreported to the police between 2006 and 2010, according to a new report published by the Bureau of Justice Statistics (BJS).  Because of this 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 incarcerating drug offenders is effective. Such effectiveness is studied in the correctional system via the ‘risk principal,’ or classifying people based on the level of risk. heinonline.org/HOL/LandingPage?handle=hein.journals/fedsen27&div=37&id=&page=
Relying on official statistics can be problematic to grasp a correct understanding of crime in society because many crimes never even come to the attention of the criminal justice system. Official statistics are often the crimes that are known or reported to police or others. 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
My father-in-law grew up in a small town in South Dakota. When they moved to Colorado, they still had a rural mindset to their property. They often think people should not touch other peoples things, so there is no need to lock up their house, car, or other property. He leaves his vehicle, house, and garage unlocked in Colorado because of that mindset. However, they live in a large, populous part of Colorado in a suburb outside Denver. Most people do not know the neighbor three doors down. One morning he woke up to his truck gone! The first thing he did was realize he left the keys in the truck and the truck was unlocked (normal to him). Next, he decided to take a walk to look for it before phoning the police. He located the truck, and it was damaged. It appeared that kids took it for a joy ride, as evidence from the beer cans and odor. He chose not to call the police. Why? He was happy the property had was located, yet he believed ‘it was his fault,’ and he had to get to work. Is this type of reaction more common than we may think?
A friend of mine was a victim of domestic violence for over nine months and never told anyone, especially police. Her boyfriend was only presented as perfect, loving, and romantic on social media and around people. When she did come forward, it was after she landed in the emergency room due to him assaulting her. People may initially think domestic violence victims would always call the police, but there are so many reasons people do not come forward.
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. 
Some Reasons People May Not Report 
- Bureau of Justice Statistics. (2012). Nearly 3.4 million violent crimes per year. https://www.bjs.gov/content/pub/press/vnrp0610pr.cfm↵
- 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. ↵