Prince George's County Police Officer Peter F. Morgan was found guilty by a police trial board yesterday of violating departmental rules on the use of deadly force when he fatally shot an unarmed, fleeing shoplifting suspect last Christmas Eve.

The three-member panel reached its verdict with one dissent after 75 minutes of deliberation.

Punishment could range from a reprimand to dismissal from the force. It will be determined by Police Chief John W. Rhoads after the trial board makes its recommendations.

The two-day trial board hearing at police administration headquarters in Forestville climaxed yesterday with Morgan's defense that "I did what I had to do, in my mind, to protect the citizens of the community."

The shoplifting suspect, 32-year-old William Ray, who had been a drug addict, had stolen two hams worth $18.58 and was being processed at the Seat Pleasant station when he broke away form Morgan. Minutes later, in an alley across Madison Road from the station, Morgan felled Ray with a single bullet to the back of the head.

The shooting of Ray, who is black, by the young, white officer was followed by a second fatal shooting of another black suspect by a different Prince George's officer a few weeks later. The incidents revived old charges of racism against the Prince George's police.

Following the two incidents, Chief Rhoads toughened guidelines on the discharge of firearms.

Emerging from the hearing room after yesterday's verdict, Morgan bitterly described the entire proceeding as "tainted."

"It's a political year," said Morgan, who was wearing a three-piece civilian suit. "I was a political pawn. I was guilty before I walked in the room. This was just a waste of time before I go to Circuit Court (to appeal the verdict) and get justice."

Morgan, 22, with less than two years on the force when he discharged his weapon for the first time in the fatal shooting, expressed confidence that he would ultimately "be reinstated.

Naturally, I'm a little upset because it's embarrassing."

Earlier this year Morgan was found by a county grand jury to have committed no crime when he killed Ray Dec. 24.

Asked at the outset of his two hours of testimony yesterday whether he shot Ray "because he was black," Morgan declared, "absolutely not."

Morgan testified that he had been working the desk that day at the Seat Pleasant station, whose officers patrol an area that is predominantly black and contains a disproportionate amount of crime compared to the rest of the county.

Ray had failed to post the $200 bond set for him by the District Court commissioner who works in the station, and it was Morgan's task to place Ray in a holding cell pending his transfer to the Upper Marlboro jail, he said.

Ray was "nervous and jumpy," Morgan said, as he took a syringe from the prisoner's pocket. "He stated he was shooting and trying to cut down. He was very jumpy," Morgan said. "I told him to be calm . . ."

Morgan testified he isn't "dead sure" what happened next. Others said Ray pushed the officer down, than ran out the door about 30 feet away. Morgan recovered and gave chase, pausing at the door to shout the first of three commands to halt.

Ray ran across Addison Baad, nearly causing an oncoming motorcycle to overturn, according to testimony. Morgan said he thought that the motorcycle, which apparently sped on, had thrown its riders as he pursued Ray down an alley.

"Stop or I'll shoot," Morgan said he commanded. Ray, now 60 feet in front of him and heading for a wooded area, turned around but continued running at full speed, according to Morgan, who described the foot race as a "losing battle . . . The defendant had his adrenaline flowing."

In his defense, Morgan said he considered Ray a desperate drug addict who needed a fix, had no cash to buy one, had exhibited a lack of respect for the law by pushing him aside in his escape, and had endangered the motorcyclist in his flight across Addison Road.

"I thought 'I got to stop him before something else happens,'" Morgan testified. "I figured a warning shot would stop him and it would possibly miss and there were houses and people. It was a clear shot. While running I stopped and pulled the gun up to the center of my body and shot and hit the defendant in the back. He fell immediately to the ground."

Asked to describe his state of mind at the time, Morgan said, "I was fearing if he got away he'd hurt somebody . . . It was a split second type of judgment. I'm not given time to sit down on a Monday morning and look at everything.

David Grover, the associate county attorney prosecuting the case, asserted that Ray "didn't endanger anyone in the process of his escape . . . This was not a Catch-22 incident."