Lawrence Sherman | Philadelphia's journey in the fight against crime

While this has not been a good year for crime in Philadelphia, better days may be coming soon.

The election of Penn graduate Michael Nutter as our next Mayor, and Nutter's appointment of former Washington, DC police chief Charles Ramsey as the next police commissioner holds the promise of a far more systematic effort to fight crime than our city has ever seen.

Criminologists have long debated the role of the police in crime prevention. Some argue that crime is largely shaped by social factors, with little impact from any agency of criminal justice. Others argue that what police can do will matter a lot. If the new Mayor is to make any difference, let's hope the latter view is at least partly right.

The research evidence for that view has been growing steadily for almost three decades. The National Research Council of the National Academy of Science has found that, in general, the more focused police practice is on specific places, times and people, the more likely police are to reduce crime.

One body of evidence the NRC reviewed included the tests of legal and Constitutional uses of what has been called "stop and frisk," a policy of looking for people carrying illegally concealed weapons in locations with high rates of gun crime. Seven out of seven tests of this policy - in Kansas City, Indianapolis, Pittsburgh and Colombia - have found that it reduced either gun homicides or gunshot wounds treated in hospitals.

During the mayoral campaigns, Mayor-elect Nutter advocated a more focused use of this practice in Philadelphia, gaining strong support in opinion polls of both white and African American Philadelphians. Nonetheless, many Philadelphians who support the Mayor-elect remain concerned about its potential for misuse.

In the aftermath of the tragic murder of Philadelphia police officer Chuck Cassidy, hundreds of Philadelphia police looked for a young black male suspect in high-crime areas. Before the confessed killer was found in Miami, many observers alleged that police conducted illegal searches without adequate reason to suspect the persons searched. Opponents of stop and frisk cited that as evidence of the risks of such a policy.

What the alleged abuses did not show, however, is that the stop and frisk research was wrong. While the search for a police murderer was undertaken by officers in many different units, the seven tests of stop and frisk were conducted by officers specially trained and supervised for the task.

No complaints of misuse surfaced in any of these tests. Under proper guidance, the Philadelphia police are more than capable of training such units to operate legally and politely.

Still, stop and frisk, by itself, isn't enough. A high poverty rate and other social factors have created a large population of convicted offenders, most of whom have served terms in prison or on probation.

With some 100,000 people on probation, parole or pre-trial supervision, about 1 in 15 people residing in Philadelphia is currently in trouble with the law. Another 30,000 are behind bars but will soon come out. Philadelphia has never done enough to help this group heal its own victimizations, and to become law-abiding citizens.

One place the Mayor may start is the City's Adult Probation and Parole Department (APPD). This agency has under 300 officers to manage 55,000 convicted offenders. Based on our homicide rate alone, at staffing levels found in all other counties in Pennsylvania, Philadelphia should have over 1300 officers.

The city can also place far more emphasis on the most dangerous offenders, by doing relatively little with the vast majority of probationers who have little risk of committing a serious crime. Such an approach has already allowed the APPD to create a Strategic Anti-Violence Unit, with funding sponsored by Nutter when he was a City Council member.

The idea of "triage" in criminal justice resources has even broader implications. Just as the National Academy of Science report found policing to be more effective when focused on a few "hot spots" of crime rather than spreading police evenly across a city, so to could the entire criminal justice system take the same approach. Prosecution, trial preparation and sentencing could all emphasize the cases that pose the greatest harm to the public.

The most surprising result of a risk-based approach, such as the policies developed over the past decade in Virginia, is that they can also reduce the prison population. Virginia has seen both its number of crimes and prisoners go down since it adopted risk-based sentencing guidelines. This idea is also controversial, since it places more emphasis on the criminal than on the crime. Yet sentencing policies in many democracies increasingly make that choice, including those in England and Scandinavia.

Philadelphia could reduce both crime and taxes with fewer people in prison. We have over 9,000 people in county jail, and some 20,000 in state prisons. We also have some dangerous people on the streets who would be incarcerated under alternative policies. Statisticians like Penn's Richard Berk have been able to predict which offenders will be the most dangerous, with some of them forecasted to be 75 times more likely than other convicted offenders to commit a serious crime in the first two years after they are sentenced. Penn's Jerry Lee Center of Criminology has been developing these models as a priority for Philadelphia, which the new Mayor could put to much wider use. They could even help to solve our many unsolved murders.

None of these steps will cure the deeper problems of a high poverty rate and a sluggish economy. Nutter has other policies to effectively deal with those issues. Meanwhile, it seems likely that Nutter will make the most of what criminal justice can do in fighting crime.

Lawrence W. Sherman is Director of Penn's Jerry Lee Center of Criminology and Wolfson Professor of Criminology at Cambridge Univ.

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