Prince George's County detectives have closed seven unrelated homicide cases in the past two weeks, including one in which the suspect is an 84-year-old woman in a nursing home.

Police highlighted the unusually high number of closures in such a short span but acknowledged that they are struggling with violent crime.

"We've had a good two weeks," said Maj. Vincent Gay, commander of the Criminal Investigations Division, which includes the homicide unit. "I don't think anybody would say crime is at the level the police department and community would like it. But we're making a tremendous amount of arrests."

There have been 141 killings in the county this year, seven fewer than the total for all of 2004.

Forty-eight of the 141 homicide cases have resulted in arrest or closure. About 15 percent of the closures have come in the past two weeks.

One of the cases involved the death of Joan Duckett, 65, a patient with Alzheimer's disease who was living in a nursing home in 2001 when she and an older Alzheimer's patient began shoving each other, police said.

During the altercation, Duckett fell and was injured. She died of the injuries in April. Police identified the other woman, who is now 84, but after consulting with prosecutors decided not to charge her because of her age and health.

"It's debatable what the intent was," Gay said. "We factor in all those things."

Another case involved a shooting during an apparent road-rage incident at a busy Clinton intersection during rush hour last week. Keith L. Ingaharra was shot about four times with a .45-caliber Glock pistol at Old Alexandria Ferry Road and Virginia Avenue.

Alfred L. Evans, 39, of Upper Marlboro told officers he shot Ingaharra and was arrested at the scene, police said. Ingaharra died Sunday of the wounds, and Evans was charged Monday with murder.

A third case was that of Gilbert Wood, 50, of Branchville, Va., who was fatally shot in Capitol Heights last week. Anthony Rorie, 35, was arrested at the scene and charged with first-degree murder.

Those cases differed from the norm in the county because of the ages of the victims and suspects. According to police data, the majority of slaying victims and assailants are black men ages 20 to 25.

Eighty-two percent of victims this year were killed by guns and 9 percent by knives or other sharp objects, according to a police memorandum. Five homicides were gang-related, 24 stemmed from drugs and 36 resulted from other types of arguments. Sixteen took place during robberies.

Fifty-three people were slain in a street or an open area, 20 in a parking lot and 20 in a vehicle. Most of the others were found in houses, apartments, nightclubs and motels, the memo said.

The most deadly month was May, with 18 homicides, followed by January, with 16.

Twenty-seven happened on Mondays, followed by 22 on Tuesdays, the memo said. And the majority -- 75 -- took place between 4 p.m. and midnight.

Gay said officers will continue to work diligently and make arrests.

"We are headed in the right direction," he said, "and we are very optimistic."