IT COULD HAPPEN anywhere, but the number of boisterous teen-agers hanging around the shopping centers and parking lots in Montgomery County and their behavior have come as quite a shock to new Police Chief Bernard D. Crooke. Even after more than 20 years on the city streets as a District police officer, Chief Crooke says he's astounded by the degree of outdoor drinking, brawling and drug use that police and residents must deal with in the county. But in addition to a welcome police crackdown on teen-age rowdies, the chief has some other moves in mind that he hopes will cool things in the county.

Understandably, tensions have been running high between groups of teen-agers and those citizens living within earshot of the partying. In the absence of any joint efforts to resolve their differences, each group tends to blame the police for the trouble -- residents charging that the police aren't being forceful enough, and teen-agers arguing that they are being unnecessarily picked on.

To bring together these different factions, Chief Crooke is going to do something he did successfully wn he was commander of the city's third police district: set when he was commander of the city's third police district: set up a citizens' races and interest groups, not only to discuss officers can be expected to do -- or not do -- to help them.

In addition, the chief wants to step up police presence in the schools -- not just to make arrests, but to discuss crime prevention, traffic, dangers of hitch-hiking, drug abuse and other issues of interest to young. Chief Crooke hopes these meetings will help teen-agers to see his officers as human beings instead of simply as the enemy. Certainly there's nothing complicated about these moves. They amount to little more than basic attempts to improve police-community relations. Still, the warm reactions the chief has been getting from citizen groups indicate that some good old-fashioned effort to improve relations between police, adults and teen-agers in Montgomery County was long overdue.