Three East Cambridge youths were convicted Tuesday of assaulting a Cambridge policeman on March 6.

At the same time, Judge James W. Bailey of East Cambridge District Court dismissed criminal assault charges brought by the youths against patrolman Peter E. DeLuca.

DeLuca was one of two officers who last October arrested Lawrence P. Largey, age 17, hours before Largey died in a Cambridge jail cell.

Bailey gave Gary W. Bergan, age 19, a one-year suspended prison sentence following his conviction for assaulting DeLuca. The other two youths, both juveniles, received one-year suspended sentences to the Youth Services Board.

Bergan was acquitted of another charge, that of threatening DeLuca's life. The three youths filed for appeals after their convictions. However, Anthony P. Sager, attorney for the defendants, said yesterday that the youths may withdraw their appeals.

They were accused of dragging DeLuca from his car and beating him after he stopped for a traffic light in Inman Square. The youths claimed that DeLuca voluntarily got out of his car and that he started the subsequent fight.

DeLuca recently returned to the Cambridge police force after taking a five-month voluntary leave of absence while being investigated in connection with Largey's death. A grand jury investigating Largey's death last month declined to indict any police officers.

DeLuca still faces a civil suit by the Largey family and disciplinary action from City Manager John Corcoran in connection with the death. DeLuca recently obtained a temporary restraining order barring Corcoran from holding a disciplinary hearing on DeLuca's case.