A Virginia prosecutor's decision not to file criminal charges against the Prince George's County police officer who shot Prince C. Jones Jr. to death last month angered his family, friends and local civil rights leaders, but brought relief to county police officers.

An attorney for Jones's family accused Fairfax County Commonwealth's Attorney Robert F. Horan Jr. of "legitimizing murder" and called on the FBI and Justice Department to be more thorough and fair in their investigations of the shooting.

Prince C. Jones Jr., 25, who was unarmed, was shot six times in the back by Cpl. Carlton B. Jones (no relation) early Sept. 1 after the officer had followed Prince Jones's Jeep more than 15 miles from Hyattsville to a neighborhood near Seven Corners. Horan said the officer thought he was following a drug dealer who might have been involved in the theft of a fellow officer's service weapon.

Horan said yesterday that the officer was following the wrong man.

At a news conference after Horan's decision was announced, family attorney Gregory L. Lattimer said: "Prince Jones was murdered; that fact is clear. And no matter that Mr. Horan has searched long and hard for dirt on Prince Jones or anything else to disparage his name; he has found nothing.

"We shall not rest until Carlton Jones answers in some tribunal for the slaughter of Prince Carmen Jones Jr.," Lattimer said.

He said Jones's mother was too distraught to comment.

The head of the Prince George's Fraternal Order of Police lauded the prosecutor's ruling. "No one feels worse about this than the officer himself, but it's clear that he was defending himself," said Cpl. John "Rodney" Bartlett, president of Lodge 89 of the FOP.

"He maintained after the incident that he was protecting himself, that he thought Prince Jones was going to kill him."

Mike Leibig, Carlton Jones's attorney, praised Horan's investigation for its thoroughness and its conclusion. "Carlton Jones cooperated all the time," Leibig said, adding that the officer had acted in accordance with his training and the rules of self-defense.

But Horan's decision reverberated across the region, to the campus of Howard University, where Prince Jones was a student, and to Prince George's County, where officers have shot 12 people since August 1999, five of them fatally.

"Here you have just one more situation, just one more crime that is questionable," said Edythe Flemings Hall, president of the Prince George's County chapter of the NAACP.

"I'm not saying the officers are guilty of anything, but nobody is able to explain to the community about why these things keep happening," she said. "Unless there's something to indicate that he did something wrong, [Horan's decision] will continue to strike fear in the hearts of so many citizens."

Sellano Simmons, 21, president of the Howard University Student Association, said students on campus "are really trying to get a grasp on what was justified about it."

He said Horan's decision sends a message that resonates beyond the campus among young people concerned about police excess, and he suggested that Horan might have taken a different course of action if the shooting victim were white.

"You've heard of driving while black? It's turned into breathing while black," said Simmons, a senior from North Dakota. "It's a hunt. It scares us."

Bishop Chui, a Howard senior from Cleveland, said the news that charges would not be filed in Virginia "came [as] a shock. I really don't think everybody expected it to be another slap in the face."

The FBI is conducting a civil rights investigation into the shooting, said Susan Lloyd, a spokeswoman for the Washington field office. She said it will be several months before the investigation is completed and reviewed by Department of Justice prosecutors.

Prince George's Police Chief John S. Farrell said yesterday that an internal police probe into the shooting will resume immediately and that he hopes it will conclude as "expeditiously as possible."

Horan said Carlton Jones, 32, was conducting a legitimate police operation when he tailed Prince Jones into Virginia. Horan said Carlton Jones, who crossed state lines only to conduct surveillance, believed that two drug dealers had previously driven the black Jeep Cherokee that Prince Jones was driving and that one of those suspects had rammed police vehicles in earlier confrontations.

Horan said that Prince Jones may have rammed the officer's car for fear his own life was in danger.

Ted J. Williams, another attorney for Prince Jones's family, said that Horan had failed to address the fact that Carlton Jones had no police powers in Fairfax and that in the confrontation, he produced his handgun and announced he was an officer but did not show a badge. The officer was driving an unmarked car.

Although both men were black, many police critics say the shooting shows how racial attitudes shape an officer's behavior. Black men, they say, are assumed to be more likely to break the law--an assumption behind the practice known as racial profiling. And they are assumed to be more dangerous than whites, so police tend to overreact, critics say.

"I think when young black men are involved, many officers have the mentality to act first and think later," said Michael Atkins, executive director the D.C.-based Community Alliance for Youth Action. "Those attitudes have nothing to do with the color of the officer--it's a mentality."

Horan acknowledged that his decision would be unpopular.

"I'm quite clear there is nothing I could say to reduce anyone's outrage," Horan said. "All I can do is deal with the facts."

Staff writer David Fahrenthold and Tom Jackman contributed to this report.