IT'S A GOOD NEWS story that can be told partly by the numbers. Crime is down again in Philadelphia this year, led by a steep drop in the number of homicides.

If the trends hold, Philadelphia will end 2013 with a total of about 250 slayings, about 30 percent fewer than in 2012. This is a significant decline in just one year; it also will be the lowest number of homicides recorded since 1967, nearly 50 years ago.

But, this is also a human story. It means that more people survived another year without ending up dead in the street or sitting in a cell awaiting trial for murder. Fewer widows, fewer grieving mothers, siblings and relatives.

Homicides have claimed the lives of nearly 1,600 people in the last five years and the data tells us that the majority of the victims - and their killers - are young, African-American males between the ages of 15 and 29.

Staying alive gives these young men another chance to move on with their lives, hopefully on positive paths, and escape a rendezvous with an early death.

Police will tell you that homicide is not a complicated crime. Most are crimes of passion, anger or retaliation. Experts will also tell you that it is virtually impossible to prevent a slaying that begins as an argument between lovers, partners or spouses, often inside an apartment or home.

But, there are types of homicides that have proven preventable and police and prosecutors in Philadelphia have concentrated on these using new techniques they have learned from other cities and from crime experts.

Much of the effort is data driven, but it still intimately involves the officer on the street using that information wisely.

Police Commissioner Charles Ramsey deserves credit for this change in police emphasis, for being open to new techniques, and by making sure new approaches filter down to the district level.

A good example of the new policing is how police flood the zone after a homicide believed to be gang-related. Word goes out to known gang members that police are watching. Arrests are made for violation of parole and other offenses to remove a potential shooter from the streets.

Police and District Attorney Seth Williams have a program called Focused Deterrence that identifies what they call "impact players" - people who are judged very likely to commit crimes. They are called in and offered help from social-service agencies if they need it, but promised punishment if they stray.

That said, it is hard to say for certain why the number of killings are going down. Obviously, it has to do with the new policing. Philadelphia is also part of a national trend of decline in violent crime. This year, every major crime except rape has declined in Philadelphia.

By no means are we a crime-free city. Police will still record more than 66,000 major crimes this year. But, the numbers keep going down each year and that is far better than the 1990s, when it looked as if crime would consume the city.

Mayor Nutter's goal when he took office in January 2008 was to half the homicide rate. Ramsey is convinced he can bring the number below 200 a year.

Let's pray they both succeed.