Philadelphia is on track to finish 2013 with fewer homicides than in any year since the relatively peaceful days of 1967. This is at least partly a result of sustained, focused crime-fighting strategies from the streets to the courts, a strong commitment to reducing gun crimes, and an openness to new approaches to law enforcement.

Mayor Nutter, District Attorney Seth Williams, and the judiciary should be commended for making violent crime reduction a top priority and sticking with their goal in the face of setbacks.

If the current trend continues, Philadelphia could end 2013 with around 250 homicides. The city has had about 80 fewer killings this year to date compared with the same period in 2012, a remarkable decline of 24 percent. Even one killing is too many, but considering that there were 319 over the same period in 2012, this year's figures represent a dramatic improvement.

Philadelphia's homicides peaked at 500 in 1990, at the height of the crack cocaine wars. Then the number generally fell until the mid-2000s, when the city reduced specialized crime-fighting programs. Violence mounted again, becoming a major issue in the 2007 mayoral race.

Since winning that contest, Nutter has worked to build a more sophisticated Police Department under the strong leadership of Commissioner Charles H. Ramsey. The commissioner has rearranged the command structure, appointing captains with results-oriented missions tailored to the communities they serve.

In South Philadelphia, for example, the department has employed a strategy known as Focused Deterrence. Officers have warned neighborhood gangs that if one of their members is caught committing a gun crime, the entire group will face the consequences. That includes frequent drug testing for parolees, more probation violation hearings, and even crackdowns on unpaid utility bills. The city also offers alternatives to violence such as job training.

The department has mapped crime to identify "hot spots" of violence and followed up with enhanced patrols in those areas. At the same time, the District Attorney's Office has assigned prosecutors geographically so that they can become more familiar with each neighborhood's problems and players.

Williams has persuaded the courts to set higher bails and longer sentences for the most violent criminals. The courts have also permitted the use of indicting grand juries to charge suspects, allowing witnesses to offer preliminary testimony in secret and lower the risk of intimidation - a problem that nevertheless persists on the streets.

Hospital emergency rooms also deserve credit. In 2012, nearly 28 percent of gunshot victims died; this year, the rate is down to 20 percent.

For all these successes, the downward trend in the city's violence, which echoes a national trend, has yet to be fully understood. Edward McCann, the district attorney's top deputy, said the next step is to ask researchers: "Are we building something that is sustainable?" That is the right question, and Philadelphia's leaders should pay attention to the answers.