A Northwest Washington woman, unconscious and severely beaten, was found yesterday near a popular jogging trail in a wooded area of Rock Creek Park, D.C. homicide police said. She died soon after, authorities said.

Police identified the woman as Gail Renee Ornstein, 38, of 2410 20th St. NW. Police said a passer-by, who found the woman about 2 p.m., reported that she was unconscious at the time. A D.C. medical examiner pronounced her dead about an hour later. An autopsy determined that death was caused by severe beating, police said.

Homicide Sgt. Sonny Wade said Ornstein was found in the 2000 block of Waterside Drive NW near the William H. Taft Bridge, which carries Connecticut Avenue NW over Rock Creek Park. He said police have no motive in the killing.

Police said Ornstein was an employe of DeLeuw, Cather and Parsons, a consulting engineering firm whose contracts include Metro and the Northeast Corridor rail project.

Ian Stirton, who lives in the same condominium building, said he often walked downtown to work with Ornstein. Early this morning, he crossed his bare arms and paced in front of the three-story building in the Kalorama area.

"She was a lovely person, a hard worker, by golly," he said, almost whispering. "I'm going to miss her a lot."

Stirton said Ornstein was always a cautious person, in his opinion, too cautious.

He said Ornstein and a friend used to always talk about crime and how careful people must be.

"I used to tell them they were silly," Stirton said. He said when a street lamp recently burned out in front of their building, it was Ornstein and her friend who urged him to get it fixed.

Stirton said he was working on his car when police began gathering yesterday on Waterside less than a block from the condominium. He said Ornstein sometimes parked her car near there.

"I thought, well somebody must have been killed down there," he said. "I didn't think for a minute it could be her."

Two other Washington residents were killed in two separate incidents yesterday, police said.

A Southeast woman died after being stabbed in the chest during a domestic dispute in her home.

Jessie B. Mitchell, 47, of 736 Brandywine St. SE, was pronounced dead about 5 p.m. at Greater Southeast Community Hospital, according to police.

Cleveland Mitchell, of the Brandywine address, was charged with homicide, police said. He is set for arraignment tomorrow in D.C. Superior Court.

In an earlier incident, Andre Grayson, 21, of 2705 13th St. NE, was shot to death as he stood across the street from his home, police said.

Grayson was pronounced dead at 4:35 a.m. at Washington Hospital Center's MedStar unit.