A Prince William County woman this week convinced a judge she was not guilty of drunken driving after arguing it was premenstrual syndrome, not drunkenness, that caused her erratic behavior.

Geraldine K. Richter, 42, an orthopedic surgeon who works in Fairfax County, was driving a red 1988 BMW from a friend's house about 10:35 p.m. last Thanksgiving when a state trooper noticed the car was straddling the white broken line on the Dulles Toll Road, according to court records.

After stopping her, Trooper S.M. Lunsford said he noticed a strong odor of alcohol. "I asked her how much she had to drink and she stated to me it was none of my damn business and that she was not drunk," Lunsford wrote.

He said she refused field sobriety tests. According to court records, when he asked her to put her hand on top of her head, "She turned around and tried to kick me in the groin area."

When he and another trooper tried to handcuff her, the records said, "She was saying, 'You son of a {expletive}; you {expletive} can't do this to me; I'm a doctor. I hope you {expletive} get shot and come into my hospital so I can refuse to treat you, or if any other trooper gets shot, I will also refuse to treat them."

Lunsford said that when he took Richter, who lives in Catharpin, to the Fairfax County jail, she was still cursing. When the Breathalyzer operator asked her whether she wanted to take a breath or a blood test, "Dr. Richter then drop-kicked the Breathalyzer table with her feet, and shoved the desk about 10 inches with her feet. The deputies then placed leg restraints on her feet."

After about 20 minutes, she chose the breath test, he said. She tested at 0.13. The legal limit in Virginia is 0.10. David Sher, Richter's attorney, said yesterday that Fairfax County General District Court Judge Robert J. Smith said in his not-guilty finding Tuesday that after hearing two expert witnesses -- one of whom testified about how PMS affects some women's behavior and another who testified that the Breathalyzer reading was skewed because Richter held her breath -- he had a reasonable doubt about the case.

The judge declined to comment yesterday.

Assistant Commonwealth's Attorney Grace E. Burke called the PMS argument "ridiculous" and said Richter's behavior at the scene and at the jail was consistent with intoxication.

"It is a typical case of drunk driving," Burke said. "It hurts the credibility of women. I can't tell you how ridiculous I think the defense is. She used PMS to explain away her outlandish conduct toward the officer at the scene.

"I think it defies common sense. We would all like to blame PMS," she added. "The men in the world I'm sure are just shaking their heads at this one."

Sher said his client reacted erratically only after the trooper threatened to arrest her and take her children, who were in the car, to Child Protective Services. "When they put her children {then ages 4, 9, and 12} in jeopardy, she became very upset," he said. "She was premenstrual and she became like a lioness to protect her children," he said.

Sher said PMS, which can cause women to become irritable and hostile, is a reasonable explanation for Richter's behavior.

He said he told the judge that studies show women absorb alcohol more quickly during their premenstrual cycle.

"If you had three drinks, it could be like five," he said.

Richter, who referred calls to her attorney yesterday, told the officer she had four glasses of wine at a friend's house over six hours, according to Sher.

Premenstrual syndrome, which experts say afflicts 5 to 7 percent of women seriously enough to affect their work and lifestyle, was first considered in the United States by a judge as evidence in a 1983 case of a Denver woman who stabbed her roommate.

Sher said PMS is not a legal defense but can be used "as a mitigating factor."

Paul Rothstein, a professor of law at Georgetown University, said PMS also was used as a defense in a case in England about five years ago, when an assault with a deadly weapon charge was reduced to simple assault.

Emine Cay, a gynecologist who testified as an expert witness in Richter's trial, said Richter was not under treatment for PMS at the time of the arrest and didn't know she had it.

Cay said she told the judge the situation of Richter's arrest was "exacerbated" because Richter felt her children were threatened.

According to Burke, it is common procedure that when parents are arrested and children are with them -- and there is no other adult to take them -- law enforcement officials offer to take children to Child Protective Services. In Richter's case, however, the children went with her to the jail and were picked up by a baby sitter, according to the prosecutor.

"She does have PMS, but she could have controlled it if she is not being threatened with the welfare of her children," Cay said. Staff writer Evelyn Hsu contributed to this report.