The Middlesex County District Attorney last week refused to prosecute cases against eight Cambridge youths who pleaded not guilty to charges of assaulting a bicycle rider in January

The parents of the youths, all of whom are Black, have alleged that the Cambridge Police Department arrested their children in an arbittary roundup of Black youths and treated them harshly when they were booked.

At the hearings last Friday before county judges. District Attorney Scott Harshbarger asked for a "null process verdiet in the cases because the victim of the alleged assault faded to appear before the court.

"Null process" is a decision by the district attorney not to prosecute the case because of a lack of evidence The decision is not subject to appeal and becomes a part of the delendant's criminal record unless the court specifically orders the ruling sealed.

The hearings had been scheduled for last Tuesday but were postponed until Friday because of the victim's absence Police officials would not release the name of the bicyle rider but said he lives in New York City.

But the patents of the youths, calling themselves Communities Acting Together yesterday released a statement charging that the null process request could have been interpreted as the police department having a good case but insufficient evidence to prosecute.

The decision is not sufficient because a doesn't clear the records of the youths involved." Dons Cassella, the mother of one of the defendants said yesterday. "We know the youths are innocent and we know that the police don't have a case because we have heard conflicting stories within the department," Cassella added.

Police department spokesman Timothy J. Inomey yesterday declined to common on the allegations of disagreement among police officers or on the case itself.

Officials at the district attorney's office were not available for comment.

The parents also said that the district attorney proposed a "deal" to them before the hearing promising to drop charges against the youths if the parents would agree not to sue the police department for false arrest.

According to the statement, the police department arranged the hargain after "panicking" because of parental pressure.

"We didn't take them up on it because we knew that nothing would happen if we took the case to court because our children are innocent,"Cassella said.

Toomey demed any knowledge of the alleged deal.

The incident on January I was only the first in a series of cases of alleged police discrimination brought to the attention of public officials since the beginning of the year.

Charges that police are persecuting Black youths have reached as far as the Harvard University Police Department, which parents accused of unnecessarily detaining four young Blacks last year