In Brief: Concentrating on Crime
An outsize share of lawbreaking occurs at certain places and times, perpetrated by a small group of people.
In 2020, the homicide rate soared. This was largely due to the spread of BLM riots and violence, the “defund the police” movement, and the resulting pullback in policing. University of Pennsylvania criminology professor John MacDonald teamed up with former federal prosecutor Thomas Hogan to look at another aspect of crime.
Though academics, the media, and politicians can’t seem to agree on much when it comes to crime in the United States, three stubborn facts generally apply.
First, crime is heavily concentrated by place. As a general matter, 5 percent of the locations in a given city account for 50 percent of that city’s crime. This finding has been replicated so often that it is sometimes referred to as “the law of crime concentration.” … This is not just a matter of neighborhoods: between 3 percent and 5 percent of specific addresses on city blocks generate 50 percent or more of reported crimes. And if the focus is strictly on violent crime, such as shootings, then even fewer locations — perhaps a drug house or a liquor-store check-cashing operation — are magnets for an even greater percentage of violent crime.
Are police “racist” for focusing on these problem areas? Hardly. It’s called “good policing.”
Second, violent crime is heavily concentrated in a relatively few individuals. In general, 5 percent of the criminal offenders (not 5 percent of the general population) in a given city commit about 50 percent of that city’s violent crime. One study found that just 1 percent of offenders were responsible for over 60 percent of violent crime.
Are police “racist” for focusing on certain individuals? Again, no. “The concentration of crime among people,” say MacDonald and Hogan, “reinforces the need for precision policing.”
Third and finally, crime is concentrated in time. It is predictable by hours, days of the week, and season. The small percentage of chronic offenders who generate the majority of serious crime and violence aren’t actively committing crime all day, every day. Instead, the criminal activity in crime hot spots and among chronic offenders tends to occur at night, during the weekends (Thursday night through early Sunday morning), and in the summer.
Thus, the pair concludes:
The concentration of crime by place, people, and time provides three facts that suggest crime control policy should be similarly focused on the “power few” — the small percentage of locations, offenders, and times that generate the majority of serious crime and violence. Staffing and visible police presence should peak during dangerous times. Evidence suggests that crime prevention that focuses on the power few will yield major benefits, all while not creating collateral consequences for the communities and individuals most likely to suffer from criminal victimization.
Facts are stubborn things, as John Adams reminded us. Crime is highly concentrated in specific locations, among relatively few individuals, and disproportionately during specific times of the day and year. The police know the where, who, and when of violent crime. Targeting those attributes can make law-abiding citizens safer.
