Prince George's County State's Attorney Alex Williams announced yesterday the appointment of an independent investigator to look into Monday night's shooting death of a D.C. police officer in his Largo home by a Prince George's policeman.

Williams said he found it necessary to embark on a more detailed investigation because this incident had become "very, very controversial. A lot of emotion is running on both sides."

Specifically, Williams said he wanted to avoid any appearance of a cover-up and to deal with questions about how the race of the two officers might have affected their actions.

"Some people believed that it is a black and white issue," Williams said after a news conference. Many people have contacted Williams, the prosecutor said, to express concern that the shooting "involved another county police officer . . . and a black man was dead."

To lead the investigation Williams named a longtime investigator for the state's attorney office, Alonzo Black, 42. Black in 1967 became one of the first black police officers in Prince George's County.

Black, a lawyer, will review police reports and conduct his own inquiry into the shooting death of D.C. Officer James L. Gordon, 41, by Prince George's police Cpl. Robert W. Raimond, 27.

Gordon, who was black, was in his Largo home investigating a burglary when Raimond, who is white, arrived after being dispatched on a burglary report.

Neither officer apparently knew the other was at the scene. Raimond was outside the house when he saw an armed man through a window. Mistaking him for a burglar, Raimond called out for him to freeze, according to a witness quoted by Prince George's police. The witness said Gordon turned and raised his hands in a shooting position, and Raimond shot him once in the chest.

Williams said yesterday that Black will "conduct a thorough and full investigation to determine whether criminal responsibility of any persons are warranted under the circumstances of this incident."

Black will be "exploring every concern, every issue and all relevant facts surrounding this matter," Williams said.

Earlier in the week, Williams proposed that members of the Prince George's County police, the D.C. police, and his office form an independent task force to investigate the shooting, he said yesterday. According to Williams, county police Chief Michael J. Flaherty declined the invitation but promised to cooperate with Williams' office in their investigation. Williams said D.C. Police Chief Maurice T. Turner Jr. didn't respond to his proposal.

The two police chiefs met yesterday afternoon to discuss the Williams announcement. Afterward, a spokesman for Turner said the D.C. chief would make no further comments on the shooting until the investigation by Prince George's County police is completed..

In a 2 1/2-page statement released last night, Flaherty said, "We welcome Mr. Williams' review." He said "the police investigation will stand on its own merits. A thorough investigation has taken place and is continuing. There is nothing to hide so the review will only confirm the facts that our investigators have brought forth."

Flaherty, who admitted he is "concerned about the rumors and innuendos circulating within the {D.C.} Police Department and the community," denied that his department failed to keep those involved briefed. In his statement, Flaherty detailed meetings he had this week with D.C. police officials, Gordon's family and union leaders from both police departments.

In recent days, Williams said he had received dozens of telephone calls that he described as "grumblings from Prince George's rank and file and from D.C. rank and file and citizens."

Williams acknowledged that he, too, was concerned: "There was some concern that I have in my mind. I want some facts."

Relations between the two police departments have been strained since the shooting, with D.C. officers questioning both Raimond's conduct and the Prince George's police investigation that followed.

Williams said questions have been raised about whether Gordon was warned properly by Raimond, whether prompt medical attention was administered and about when D.C. police officials were informed and allowed access to the shooting scene.

"Allegations have been made and they have been brought to my attention," Williams said. "I don't know to what extent those discrepancies go, but I would like those with discrepancies to come forward."

Black has been relieved of all other investigative duties so he can concentrate solely on this case, Williams said. Otherwise, Black's task will differ little from the state's attorney's usual investigations of police shootings.

He will review the autopsy report and all police reports of the shooting, visit the scene, speak to all witnesses, and meet with both police departments, Williams said.

Black's duty will be to "inquire into the nature, extent and impact of alleged delays in notice, and to inquire into the alleged inaccessibility of paramedics," Williams said.

When Black completes his probe, the results will be presented to a grand jury. Williams, declining to estimate how long the investigation will take, said he has not decided whether to seek a special grand jury for the case.