Report: CompStat does reduce crime

CompStat-style programs are responsible for a 5 to 15 percent decrease in crime in cities using the system, according to a recent study by the Brennan Center for Justice at the New York University’s School of Law, a nonpartisan law and policy institute.

CompStat is a data-driven police management technique, developed in New York to reduce and prevent crime. Initially done by hand and then computerized in 1994, CompStat’s management and accountability system helps police take up strategies based on accurate data collection.

The Brennan Center examined why crime rates have fallen over the past two and a half decades. Since 1991, violent crime has fallen by 51 percent and property crime by 43 percent. The Brennan Center’s analysis covered of 50 of the most populous cities. Of those, 39 had implemented CompStat.

“Specifically, a CompStat-style program is associated with a [national average of a] 13 percent decrease in violent crime, an 11 percent decrease in property crime and a 13 percent decrease in homicide,” said Inimai Chettiar, director of the Justice program at the Brennan Center, in the executive summary. In New York, CompStat was credited with reducing 63 percent of the crime in the city from 1994 to 2012.

In a separate study, the Police Executive Research Forum (PERF) found that today 79 percent of medium to large police departments use some form of CompStat. Most recently, the New York police department (NYPD) is devising a data tracking system similar to CompStat to spot trends in animal abuse, according to a NY Post article.

The database system is aimed at helping the NYPD look for animal cruelty hotspots (where crime is most likely to occur) and larger, citywide animal abuse patterns so authorities can concentrate their resources on those areas. The system should also help law enforcement spot trends between domestic violence and animal attacks, the NY Post reported.

Last September the Seattle Police department began analyzing crime data to quickly respond to hotspots and identify emerging trends. SeaStat, based on CompStat, is one of many data analysis programs used by municipalities nationwide to reduce crime. For example, in 2010, police in Memphis added IBM’s Blue CRUSH (Criminal Reduction Utilizing Statistical History) software to create predictive models by analyzing crime and arrest data, The Los Angeles Police Department is among several in the United States using PredPol cloud-based software that automatically generates maps for police of where and when crimes may occur.

And in 2013, Baltimore and Philadelphia added predictive analysis tools to predict which prison parolees are likely to commit murder and therefore should receive more stringent supervision. Richard Berk, creator of the algorithms behind the analytics, said the software draws on known predictors, such as a the age of the parolee when the crime was committed, the nature of the crime and the parolee’s address to create its predictive analysis.

The Brennan Center study analyzed a variety of reasons why crime has dropped. Its biggest finding: increased incarceration had a limited effect on declining crime rates. Since 2000, the effect on crime rates of increasing incarceration has been essentially zero. The United States has 25 percent of the world’s prisoners and has incarcerated a higher percentage of its people and for a longer period than any other democracy, the report noted.

In addition to CompStat, the report also found that an aging population, changes in income, and decreased alcohol consumption affected crime rates. Consumer confidence and inflation also seem to have contributed to crime reduction, according to reviews of other past research, according to the report.