Fairfax County police charged an Annandale woman yesterday with murdering her estranged husband, who was gunned down March 6 at the family home on the eve of the couple's divorce.

Patricia Schaefer, 46, was arrested about noon at the two-story brick colonial and charged in the death of Richard Schaefer, 53, police said. She was being held at the county jail in lieu of $200,000 bond, they said.

Richard Schaefer, who had been living in Lakewood, Colo., had scheduled a 7:30 p.m. visit with several of the couple's six children. He was killed on the front porch in the 3900 block of Prosperity Avenue. Neighbors said they heard as many as seven shots coming from the house.

A source said that Patricia Schaefer and three of the children were at home when the shooting occurred but that there has been "a total lack of cooperation" from the family in the investigation. Patricia Schaefer's attorney in the divorce case, not family members, called police to the home, where Richard Schaefer lay dying on the front porch from multiple gunshot wounds, the source said.

Hours after the shooting, police searched the home and seized items including a revolver, a partial box of ammunition and spent bullets and casings, according to court records.

Five weeks after the shooting, Quinn Schaefer, 18, and his mother pleaded no contest to charges that they had tried to break into the victim's Colorado house, an official at the Lakewood Municipal Court said yesterday. They were each fined $100 on the charges of "trespassing into a dwelling" on April 16, she said.

Jane Carmichael, who rented rooms in her Colorado home to Richard Schaefer, said in a phone interview that she called Lakewood police after a woman and young man scaled a six-foot privacy fence and tried to enter her home through the ground-level doors and windows.

In court papers filed in Fairfax Circuit Court since the shooting, Patricia Schaefer said she went to Colorado "to secure approximately $3,600 on deposit with a Denver bank in the sole name of Richard K. Schaefer" because a savings and loan association was threatening to foreclose on the Annandale home. She stated that she and her children were entitled to survivor benefits, for which she had applied.

Patricia Schaefer declined to be interviewed yesterday; her attorney could not be reached for comment.

The couple had been embroiled in a bitter divorce case that was scheduled to end the day after the shooting. Several weeks before the shooting, a commissioner in chancery assigned to the divorce case found that Richard Schaefer had been subjected to "vicious physical attacks, severe and unjustified verbal abuse and would, if requested, be entitled to a divorce on the grounds of physical cruelty."

The physical abuse included pulling his hair, striking him with a tool box and window shutters and attacking him while he was sleeping, the commissioner found. "She also struck him in his face with her hands and threatened him with a potato peeler," the commissioner wrote.

When she filed for divorce in 1987, Patricia Schaefer claimed that she, not her husband, was the victim of physical abuse.

Al Ossinger, a chemist with the Environmental Protection Agency in Lakewood, said he had known Richard Schaefer, a retired economist with the U.S. Bureau of Mines, since 1959. He said Schaefer was hoping to get a position teaching economics in Colorado and was doing volunteer work for the Environmental Defense Fund and the Colorado Mountain Club.

"When he left {for Fairfax}, he was looking forward to getting his divorce behind him," said Ossinger. Hoping he would be granted custody, Ossinger said, "he wanted to bring some of his children out to introduce them to the mountains."