How To Understand New Jersey Crime Statistics

An ACLU of New Jersey Primer

Understandably, and often laudably, mayors and police chiefs publicly tout decreases in crime in their municipality. Unfortunately, however, officials sometimes present a rosier picture to the public by manipulating key pieces of data.

Following the New Jersey Attorney General's release today of the state's 2009 annual crime statistics, the ACLU-NJ offers a primer for citizens and journalists - and citizen journalists, for that matter - to ask the right questions and use a critical eye when reading a "crime is down" press release, and for getting up-to-date information without waiting for a state crime report that's issued ten months after the end of the calendar year.

Starting at the Scene: Police Agencies, the Crimes, and their Perpetrators

In addition to the individual police departments in most New Jersey municipalities, a variety of specialized public law enforcement agencies also have police forces, including New Jersey Transit police and Rutgers police, among many others, that operate within some jurisdictions.

Each department prepares monthly crime reports containing a wealth of information, as required by state law. The reports (known as the UCR-365, UCR-370, and UCR-370u18 forms) count the number of "index" crimes reported and solved: murder, rape, robbery, aggravated assault, larceny-theft, burglary, auto theft, and arson.

They also break down the number of total arrests by age, race, gender, and ethnicity. Under the state's Open Public Records Act, individual citizens or groups may submit requests to the municipal clerk for municipal departments, or to the designated records custodian of the specialized department, to access and make copies of these filings.

Government and DIY Number-Crunching

Every fall, the New Jersey State Police compiles the year's crime trends in New Jersey based on index crimes and other data from New Jersey law enforcement agencies to calculate the crime rate per 1,000 people. For example, statewide in 2009, there were 3.1 violent crimes (murder, rape, robbery and aggravated assault) per 1,000 people and 20.8 nonviolent or property crimes (larceny-theft, burglary, auto theft and arson) per 1,000 people.

The state crime report provides similar numbers for every municipality in the state, but citizens can easily calculate this information using the monthly crime reports from every town's police department. If specialized police departments operate extensively within the town, it is important to collect their data as well.

Questions to Process the Numbers

Data alone can't tell the real story - only asking certain questions can.

  • First: if a town issues a blanket statement pronouncing a decrease in crime, citizens need to analyze which crimes have gone down compared to last year, and which have gone up. Additionally, how does a particular municipality' crime rate compare to neighboring towns or the state as a whole?
  • Another important question: when crime reportedly falls, what range of time serves as the basis for the comparison? For example, if auto thefts fell 17 percent in one town, is that number based on the difference between 2008 and 2009, or is the window longer? The year-to-year trends may say one thing, while a three-year comparison may say another. It's misleading, for example, to announce "crime is down 21 percent" based on numbers from three years ago if crime has increased from the previous year.
  • Third: how did a town perform compared to other towns and statewide trends? For example, if auto theft in one town fell 18 percent during a year where auto theft decreased 23 percent statewide, these broader trends may have played a larger role than local police. Even if crime rates drop from a previous year, it's important, if local enforcement fell short of the statewide rate - to ask why, especially when advocating for changes in police tactics or police staffing.

These same questions should be asked for all crimes. A town with annual increases in rapes and murders might still proclaim that "crime is down" if the number of robberies and burglaries has decreased. Unless the data come in context, bold statements about crime statistics are incomplete.

Questions to Target the Statistics Themselves

Besides putting the numbers in context, advocates can look for problems with the data itself. Are certain races or ethnicities targeted disproportionately to the demographics of the town? And if so, is it from unethical practices like selective enforcement and racial profiling, or could more benign circumstances explain a disparity?

Another key marker to look for is the "clearance" rate, based on the number of crimes solved and perpetrators arrested. For example, the 2009 state crime report listed a clearance rate of 53 percent for murders and 58 percent for aggravated assaults. For accurate context, the local police department's numbers would have to be compared to statewide rates. A town that solves only 32 percent of murders and 41 percent of aggravated assaults, for example, might demonstrate a need for better training or more detectives, which is something citizens can advocate for with their mayor or municipal governing body.

Learning by Example

Earlier this year, the ACLU of New Jersey made a request for these records to the police departments of some major New Jersey cities. To illustrate how we requested this data, we have posted our request letters, the municipality's response, and a spreadsheet we prepared to analyze this data for the City of Newark. This data does not cover the other specialized police agencies that operate in Newark, which explains why this data - for the NPD alone - differs from the municipal totals. Nevertheless, it's a good example of the kinds of data citizens can expect to get when they make a request for these crime records.

Just the Facts

As with most general statements, a government proclamation that "crime is down!" should always launch deeper research to dig into the facts. Government officials are obligated to be honest and forthright in making public statements to citizens, but it's just as important for citizens to take up the obligation to hold them accountable if they fall short.

Related Content

Using the New Jersey Open Public Records Act (OPRA), the ACLU of New Jersey sought and obtained raw crime statistics from the Newark Police Department and several other municipalities around the State. Our request letter, and the responses from the Newark Police Department, are linked below.

Citizens can make similar requests from their towns using OPRA.

January 2009

February 2009

March 2009

April 2009

May 2009

June 2009

July 2009

August 2009

September 2009

October 2009

November 2009

December 2009

January 2010

February 2010

March 2010

April 2010

May 2010

June 2010

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