About 200 persons gathered in Upper Marlboro yesterday for a rally and motorcade in honor of Prince George's County police and the "silent majority" in the county that, the demonstrators said, supported the police and understood their frustrations.

The rally was organized by Tim Manley, a 23-year-old clerk in an unemployment office and a resident of Riverdale, who said that he thought he had to act after the verdict in the trial last month of Terrence G. Johnson, the 16-year-old black youth who shot two white police officers last June.

Johnson was found guilty of voluntary manslaughter in the death of one of the officers, and not guilty by reason of insanity in the shooting of the other.

"The most tragic thing that ever happened in this county was two weeks ago when the jury came back with the verdict that they did," Manley told the crowd. "I felt I had to speak my piece."

Manley and several speakers from the county's Fraternal Order of Police lodge focused on the verdict as an injustice and as proof that, as one speaker put it, "the criminal justice system doesn't work anymore."

Suzanne Sawyer, the president of the FOP'S Ladies Auxiliary, which helped Manley distribute the 8,000 flyers promoting the rally last week, also spoke of the community's "frustration" with "unbelievably staggering crime rates," inadequate support for police form the county government and "damaging media coverage."

Manley returned to the speaker's podium after sawyer spoke and won cheers by suggesting that the demonstrators cancel their subscriptions to The Washingto Post for 90 days becuase of "unfair coverage."

"As far as I'm concerned, they are all communists," Manley said of The Post.

Many of those in the crowd were police or their relatives, wives, and friends. Others, however, described themselves only as "concerned citizens."

"If the community doesn't come out and support their police," said Grady Glover, a salesman who found a flyer for the rally on his car outside his home in New Carrollton, "nobody else is going to support them."

With one exception, the crowd was also entirely white, but Manley and other speakers denounced arguments by some black community leaders that the police's problems and the Johnson case revolved around racial issues.

"I think the leaders of the black Ku Klux Klan in Prince George's County ought to go back into their communities and say they were wrong," said FOP President Laney Hester, refering to the black leaders who supported Johnson against the police. "They should say that racism was not the issue in the Johnson case. Murder was the issue."

Following the speeches outside the county administration building in Upper Marlboro, the crowd traveled by motorcade to the Hyattsville police station, where the shootings of the officers occurred last June 26.

If the people aren't going to come out here and support us," Manley declared, "we are going to make sure that they see us." CAPTION: Picture 1, After the rally, the crowd traveled by motorcade to Hyattsville police station. By Douglas Chevalier-The Washington Post; Picture 2, Crowd that gathered yesterday in Upper Marlboro heard speakers from a Fraternal Order of Police lodge. By Douglas Chevalier-The Washington Post