This year, the news is even better: Serious crime is "nominal," police reports read. Violent crime is already down another 12 percent from last year's levels. But that still means that by the end of March, violent crimes had already been reported in Cambridge 105 times.

Despite the positive trend, much remains to be done, and CPD says they can't do it alone.

A picture of Cambridge's average violent criminal, police explain, would depict a teenage male under the influence of drugs or alcohol--and therein lies the biggest hope for further reductions in violent crime: early intervention programs.

In addition, many of the violent offenders in Cambridge are not city residents, making preventive measures more difficult to develop and less likely to stamp out crime.

Chalk Outlines

Cities the size of Cambridge average six murders a year. Cambridge's average is roughly half that. Precisely because they are so rare, each individual murder in Cambridge is indicative of a larger problem, police say.

Last Christmas Eve, a brawl erupted in the CambridgeSide Galleria parking garage. Police still don't know what led the two groups involved to begin fighting, but the episode ended when Gary M. Chatelain, 20, of Roslindale, Mass., was shot and killed (please see sidebar).

The incident, police say, indicates two larger trends.