For the first time in a long time, Northern Virginia chiefs of police are finding that they actually have time to sit back and survey their domains and ask themselves some basic questions about law enforcement.

The reason is simple. The incidence of reported crime, region-wide, is down--and not just by a little bit. In the two most affluent jurisdictions, it's down by double-digit percentages.

In Fairfax County, for instance, reported crime for 1982 is down 11.6 percent compared with 1981. That's the the lowest crime rate the county has had in a decade. In Arlington County, 1982 crime is down by an even greater amount: 17 percent--an astounding drop and the lowest rate there in nine years.

Even in urbanized Alexandria, crime has dropped by an estimated 6 to 7 percent, while in burgeoning Prince William County, the number of reported crimes for 1982 is expected to be below that recorded in 1974, despite a continued if slowed increase in population.

The reason offered by the chiefs for this precipitous drop is as interesting as their insights into what can be done to continue to improve the record:

Citizens, they said, are becoming involved in crime prevention.

In a luncheon with Washington Post editors and reporters last week, chiefs Charles T. Strobel (Alexandria), William K. Stover (Arlington County), Carroll D. Buracker (Fairfax County) and George Owens (Prince William County) all pointed at citizen Neighborhood Watch groups which, they said, have reduced crimes because their presence scares off those who would commit them. (For an edited transcript of the luncheon, see Page 7 of The Weekly.)

In one community that instituted a program of community awareness, Strobel said, crime dropped by 98.2 percent over a 10-month period. Such success has been mirrored in Fairfax County and so excited Buracker, who last month honored nine citizens for heroism (see story on Page 8 of The Weekly), that he is attempting to arrange for President Reagan to address the annual dinner given by county police for Neighborhood Watch groups.

It was with a great deal less enthusiasm, however, that the chiefs considered how their fight against habitual--or repeat--offenders is going. Strobel got his fellow chiefs to nod their heads in agreement and frustration when he recounted one tale of woe:

Seems his officers had managed to arrest a several persons believed to be responsible for a series of robberies only to see one of them released almost immediately on personal recognizance-- i.e., no bond whatsoever. The next night, that person was arrested again in connection with a robbery at a Pizza Hut a few hours earlier. Then he was released a second time, this time on a $2,500 bond.

Those responsible, according to the chiefs? A handful of too-lenient judges and magistrates.

That's not a new answer. Police have been complaining for years that often they arrest someone only to find that the person they arrested is back on the street before they can complete their paperwork.

What is new, however--to these ears, at least--was a suggestion by Buracker about what can be done to get those responsible to change their tune.

Buracker suggested that citizens get involved in watching judges in action, just as they now watch for neighborhood crime and just as they have scrutinized and criticized police departments in recent years: Get in the courtroom and the magistrate's office. Sit down and watch. If someone seems to be too lenient, then say something about it and back it up with figures.

Mothers Against Drunk Driving, a Fairfax County group that has had enormous impact both locally and in the current session of the Virginia General Assembly, has been doing just that in traffic court. Law officials say judges and prosecutors and legislators are taking notice.

Whether it will work is a question only experience would settle. Whether it should be done at all, however, is something I'm sure both judges and magistrates will want to see considered before anything is done, especially since the independence of the judicial arm of law enforcement has long been seen as a bulwark against both tyranny and the abuse of individual rights.

What do you think?