A 27-year-old man was shot and killed by a Prince George's County police officer yesterday afternoon after the officer responded to a reported domestic disturbance at a Suitland apartment complex.

It was the first fatal shooting this year by a county officer, and the second shooting this week by a law enforcement officer in Prince George's County.

Alan Bernard Jackson, of 4864 Eastern La., was shot several times by the officer about 2:40 p.m. after Jackson opened the door to his apartment and pointed a loaded .38-caliber handgun at his estranged wife and the resident manager of the apartment complex, who were standing outside the apartment, police said.

The officer, Cpl. H.E. Johnson, fired his service revolver after Jackson ignored his orders to put down his handgun, said Maj. James Ross, head of the county police Criminal Investigations Division. "Our preliminary investigation shows that he acted lawfully and properly within the guidelines of the department's general orders," he said.

Johnson accompanied Jackson's wife Janice Jackson and the resident manager to the apartment at their request, police said. Janice Jackson had moved out of the apartment on Sept. 8, Ross said, after Jackson threatened her with a gun.

The manager called Janice Jackson yesterday because she had received complaints from neighbors about a water leak at the apartment, Ross said. When Jackson opened the door, he was carrying a weapon, Ross said. He then pointed it at his wife and the resident manager, Ross said.

"Statements from the people there were that Johnson quickly jumped in front of them and ordered Jackson to drop his weapon," Ross said.

Johnson fired several shots, Ross said. An autopsy will determine how many times Jackson was hit, police said. Jackson was taken to the Prince George's Hospital Center, Ross said, where he died at 3:50 p.m.

Johnson was placed on routine administrative leave, pending the outcome of the deparment's investigation into the shooting.

In an incident Monday morning in the parking lot of a College Park restaurant, an off-duty Maryland state police trooper shot and wounded two men, one of them seriously, who allegedly jumped on the officer when he tried to break up a fight, county police said.

Trooper Ralph Lilly, 22, who had been with the department for a year and was still on probation, had been drinking in a nearby nightclub before the shooting, officers said later. But police do not know whether Lilly was intoxicated because he did not give a statement to investigators, on the advice of his attorney.

Both cases will be reviewed by a county grand jury under a new policy instituted last week by State's Attorney Alex Williams. The policy calls for a routine review of all shootings by county officers in which the victim dies or receives a life-threatening injury.