A Cambion offical was charged yesterday with assaulting a union picketer while, in a separate action, a striking worker was found not guilty of company allegations that he broke windows at Cambion's Cambridge plant.

A clerk of the Middlesex County District Court issued a complaint against Bruce Rockcastle, industrial relations manager for Cambion, on a charge of assault and battery on Marie Louisa Arruda.

According to Allen Rosenberg, attorney for Local 262 of United Electrical, Radio and Machinery Workers of America, Arruda said Rockcastle "propelled her across the sidewalk by a blow to her chest with his elbow" in a picket-line incident on the afternoon of September 21.

Rockcastle is scheduled to be arraigned October 14.

In trial yesterday morning a Middlesex District Court judge found Martin Sousa of Arlington not guilty of a charge of "malicious destruction of property" for breaking windows at the Cambion plant April 26.

Numerous arrests and violent incidents have characterized the six-month strike.

Last month four Cambridge policemen received suspensions of five to fifteen days after City Manager James L. Sullivan investigated charges of police brutality in connection with a May 8 incident in which 15 union picketers were injured.

The National Labor Relations Board is scheduled to begin to prosecute Cambion November 17 on charges of refusal to bargain in good faith.

Two years ago the NLRB ruled against the company in a case involving two Cambion workers who were illegally fired for participating in a union organizing drive