In the strongest public condemnation of the management of the Harvard Police Department to date, a union steward in the University security guard unit this week said his bosses engaged in a "pattern of retaliation" against guards who accused their supervisors of discriminatory practices.

The charges made by Stephen G. McCombe, a eight-year veteran of the unit, elicited immediate response from a top security official, turning a long, simmering public controversy into an angry and personal war of words.

McCombe said actions of four administrators had the effect of discrediting the guards and permitting retaliation against them. He identified the four as Police Chief Paul E. Johnson, Manager of Operations for Security Robert J. Dowling, Assistant Director for Finance and Administration Brian D. Sinclair '62 and the University's Associate Director of Labor Relations Carolyn R. Young '76.

"I can only go on what I've seen, but to me they are retaliating," said McCombe. "By what I've seen--which is a policy of treating one group different than the other--there are discriminatory practices."

Yesterday, Dowling broke a long silence on the issue of alleged mistreatment of guards. Dowling said McCombe had coerced guards to come forward with unsubstantiated claims of on-the-job discrimination. And he challenged McCombe to a debate over the charges.

"Mr. McCombe makes statements that he can't back up," said Dowling. "I don't have to discredit him. He does that himself."

Dowling said McCombe had engaged in a personal vendetta against him. He said McCombe, in trying to hurt Dowling's reputation, had duped several guards into wrongly believing--and The Crimson into reporting--there are discriminatory practices in his unit.

Dowling repeatedly stressed that guards had had a full hearing of their charges. And he encouraged any guard who honestly believed there was discrimination to cooperate with an investigation of the unit currently being performed by General Counsel Margaret H. Marshall.

"I asked for this investigation time and time again," Dowling said.

As a steward, McCombe has represented dozens of guards who have filed grievances contesting discipline meted out by the department's management. He also represented five of the seven University guards who have charged on-the-job harassment.

In interviews last spring, each of the seven guards said they were not coerced into making their charge.

Based on his experiences as a steward, McCombe said the four administrators--as well as former General Counsel Daniel Steiner '54 and Director of Human Resources Diane B. Patrick--failed to adequately address allegations of discriminatory practices in the unit. Separate investigations conducted by labor relations officials Young and Patrick, who used to work for Steiner, failed to interview guards. The investigations cleared the supervisors.

"They try to find a way to sweep it under the rug," said McCombe. "Carolyn Young had the opportunity and Diane Patrick also to investigate the department. They could have done away with all this problem."

McCombe said Sinclair and Johnson, who often preside at meetings to mete out discipline, condone discriminatory practices in the unit.

But Young said yesterday that she had not participated in or condoned any retaliation in the unit. She said she had consulted with members of the security department on some personnel matters, but would not comment on specifics.