An Arlington judge has sided with county police who went to the aide of a woman attempting suicide, then arrested her after allegedly finding cocaine in her purse.

Circuit Court Judge William L. Winston said the officer who found Karen Ann Robb, 25, trying to kill herself in a gas oven last May "would have been remiss in his duties" if he had not searched a plastic film container in her purse while determining her identity and whether she had taken any drugs.

Police said the officer found half a gram of cocaine in the canister.

"It would be unreasonable to assume . . . that the emergency was a sham and that the search was not done in good faith," Winston said in a letter dismissing Robb's request that the evidence from the search be suppressed.

Robb's attorney, Jonathan Shapiro, had argued that police had no right to search the canister because the officer had already found Robb's identification on her checkbook. Shapiro also contended that the policeman had no reason to believe that any medicine she might have taken would be in the film canister.

"I was really disappointed" with Winston's decision, Shapiro said."That should have been won."

If Robb is convicted, Shapiro said, he will appeal the case to the Virginia Supreme Court, which he said has never ruled in a case with such circumstances.

Robb, who said she was given the cocaine by a friend "to help me stay up all night because I was going through some problems," faces a possible prison sentence of one to 10 years.

According to Robb, she was staying at her boyfriend's house near Crystal City in Arlington when the incident occured. She had argued with him, she said, and also had been depressed about her family and her work as office manager for a Capitol Hill real estate company. She also said she had just dropped out of classes at the University of Maryland because of low grades.

That morning she had thought about jumping off Key Bridge, she said, "but I couldn't drive because the cops had put a boot on my car."

Robb said she went back to her boyfriend's house, turned on the gas oven jets and struck her head inside.

A house painter at work on the house discovered her and called police and the Arlington rescue service.

According to Winston's letter, Robb "was uncooperative and when asked her name did not give it, but stated that her purse was in the living room."

Citing evidence at a hearing earlier this month, Winston said the police officer emptied the purse and as a part of standard procedure during emergencies involving uncooperative victims, searched for mediation she might have taken and for her identity.

The officer opened a black plastic film canister from Robb's purse, Winston said. "When opened it contained a piece of paper folded to contain the suspected cocaine."

"Here it is obvious that there was an emergency and that the police officer assisting the paramedics acted in good faith for the benefit of and protection of (Robb)." Winston ruled.

Robb's trial is scheduled for Oct. 10.