On Sunday, when Prince George's County policeman Bill Lowry and his partner handed out a speeding ticket in their Seat Pleasant district, the recipient said. "Thank you for not shooting me."

That same day, another man they ticketed turned to his 3-year-old in the back seat. "I want you to look at these men," he told his child loud enough for the officers to hear. "They are your enemies. They are going to kill you. Never talk to them."

Lowry said he made no response to the remarks although "inside, it kind of tore me up. It depressed me."

Lowry and his partner are white. The drivers in the cars they stopped were black. The exchanges between them took place in a section of the county where police community relations sometimes have a raw edge - an edge sharpened in the last five weeks by the fatal shootings by white police officers of two unarmed suspects, both blacks.

Vocal blacks have cited these shootings to support their charges of racism and brutality in the Prince George's County Police Department. Officers such as Lowry, in turn, have their own stories - like the ones about the traffic tickets - to illustrate their side.

The officers in the Seat Pleasant district are generally of one mind in regard to the shooting incidents: They were judgment calls - Right or wrong - but not racially motivated.

Four of every five of the 104 officers are white in the Seat Pleasant station, a white island in a predominantly black area. Here, the Prince Georges County police say they bend over backward to avoid confrontations and spend far more time helping people than hassling them.

That is why, several officers interviewed this week said> they resent the picture of them they say is conveyed by critical black leaders through the media and accepted by many citizens.

"You've got to consider wrongs done before any of us were born, skepticism toward police and the lack of understanding of what we do," said Douglas Murray, 25, a black officer who nonetheless strongly defends fellow officers. "Sometimes, people don't allow us to help them, there's so much mistrust," he said.

"It gets to you after a while; it affects you inside," said Lowry, whose more than four years as a policeman have been spent entirely in the Seat Pleasant area.

"A lot say it dosn't affect them, but it does. After a while, you can start developing the attitude: 'Screw them.' You try not to let things get to you, to treat every person as an individual, but I'd be a liar if I didn't say I have an attitude toward certain people as a result if these experiences."

Lowry's bitterness is not unique, but neither is it universal among Seat Pleasant officers.

"It's upsetting. It's not pleasant," said Gordon Scott, a 30-year-old veteran of the Baltimore city police with one year in Prince George's. "But I honestly don't believe many people feel that way" toward police.

Scott has been called names. Just the other day, his presence at the seving of a warrant by county sheriff's deputies evoked cries of "murderer" directed at him. He dismisses such occurrences as the reaction of people "under stress."

The Seat Pleasant district extends from the District to the Beltway between the Pennsylvania Railroad and Suitland Parkway. Sector "G," north of Central Avenue, has more blacks and more crime, according to census and police statistics.

It is a hilly area that includes older communities of single-family homes, many apartment complexes, a warehouse district, Landover Mall and a few patches of remaining countryside. In the G Sector last year, police logged nine murders, 59 rapes, 398 robberies, 239 aggravated assaults, 1,562 burglaries, 167 larcenies and 449 car thefts.

In spite of its reputation among police as a tough (D.C.) "line" assignment, there are huge chunks of time when almost nothing seems to happen.

It was like that on the 4 p.m. to 2 a.m. shift last Friday. The eight officers who attended roll call watched a videotape of Chief John Rhoads discussing the use of guns only in cases of "clear and present danger."

Privately, officers expressed concern that the chief's imminent new order on use of guns could encourage criminals while tying the hands of police.

In the course of officer Dave Burns' evening that followed, however, there was little danger present, clear or otherwise. There were several false alarms in the industrial park district north of Landover Road, tow fender benders with virtually no acrimony, a couple of domestic disputes smoothed over without resort to any weapon other than quiet persuasion. No arrests were made.

"A majority of people in all these communities are law-biding citizens, and a majority of them accept the police as police and not as black and white," said Burns, who became a Prince George's policeman six years ago because there were no openings in his desired field as an air traffic controller.

Burns, who is white, acknowledged that there are problems. They are reflected, he said, in the unwillingness of many citizens to provide information to inquiring police. "I don't know if it's black or white or what," he said. "I think it's just a suspicion of the system."

Burns has also been accused of racial prejudice by blacks he has stopped for driving offenses, he said. "I say nothing," he said. "I figure if that's the way they feel, nothing's going to change their minds.

"I'm just easy-going. It doesn't really bother me," he said. "I've only lost my temper a couple of times. Some people might say I back down, but I don't . . . I'd just as soon walk away from somebody as argue, but if they confront me even while I'm trying to bow out gracefully, if I have grounds to arrest them, I will.

"I'm not unique, but I'm not typical either," Burns said, as he steered his cruiser down the George Palmer Highway to respond to a report of a "disorderly female" at the Palmer Lounge. "Now, I'll go on this call and blow everything I jsut told you," he joked.

He didn't. At the lounge, a black bar just over the District line, the manager asked Burns to get the woman's name and address so that, next time she came in, he could obtain a trespass warrant to keep her out.