THE CAMBRIDGE POLICE Department desperately needs to improve its relationship with the community and should act now to rectify a deplorable situation. Complaints of police brutality and misconduct continue to rise each year as public trust and faith in local law enforcement officials declines steadfastly. At the same time violent crimes have increased here, in part due to haphazard police protection in certain low income neighborhoods.

Compounding the problem of inefficient law enforcement is the glaring disparity between the percentage of black residents in Cambridge and the percentage of black patrolmen and supervisory officers in the police department. The addition of blacks to the force is sorely needed to eliminate the numerous misunderstandings and alleged racist abuses that occur between white patrolmen and non-white citizens. The fact that the police force now has only five permanent black patrolmen and no black supervisors is a disgrace.

One immediate step the police should take to improve community relations is to proceed with speed and impartiality in next week's department hearings for Officers Francis Burns and Robert Ahern, two policemen accused of beating Clarence Anderson, a black man, on July 11. A demonstration that the department can "police itself" and provide citizens with a viable course of redress for police misconduct is essential if public faith is to be restored.

But the prospects for an improved police-community relationship are not good, at least in the immediate future. The circumstances surrounding the death of 17-year-old East Cambridge resident Larry Largey in a Cambridge jail cell two years ago remain unknown today because of the failure of police to carry out a thorough internal investigation.

POLICE BUNGLING in the early stages of its investigation of the Clarence Anderson case severely damaged the department's credibility with the public. Police officials acted irresponsibly by failing to inform the community fully about the August break-in at police headquarters and the apparent copying and possible theft of tapes used in the Anderson investigation.

As a broader goal, chapter 31 of the General Laws should be amended to transfer the responsibility of investigating police misconduct complaints from the police department and city manager to a civilian police commission. Citizens should not tolerate a police department that is incapable of thorough internal investigation and impartial disciplinary hearings. Should Cambridge police mishandle the hearings on the Anderson case, the public should press city and state policy makers to effect a wholesale change in the system.