A body found in Fairfax County Sunday was tentatively identified by police yesterday as that of a 51-year-old Arlington woman who escaped through a window of the Northern Virginia Mental Health Institute where she had been committed by her husband.

Two teen-age youths found the body in a densely wooded area about 10 miles from the institute, police said. An autopsy will be performed today, but the tentative identification of Carolyn Lindsay was made based in part on a brown coat that was found hanging from a tree, they said.

Bruce Lindsay said he believes his wife, who he said was suffering from depression and had been hospitalized previously in Arlington, escaped from the facility with the express intent of killing herself.

He said yesterday that he had his wife involuntarily committed to the mental health institution on Dec. 23. He said he was notified the next day that his wife had left the facility.

"I'm madder than hell that they let her get out," said Lindsay, an executive for United Services Life Insurance in Arlington. "It should be prima facie when you commit someone that you're going into a secure place."

Dr. Robert Strange, director of the institute at 3302 Gallows Rd., Falls Church, said an "escape warrant" was obtained from police immediately after Carolyn Lindsay was discovered missing, and a missing persons' report was filed on Jan. 14 at the request of the family. But police said the escape warrant was merely a detention order, requesting her return to the facility if located.

Strange said it is the policy of the institute to obtain such a detention order when patients escape from the facility. He said that last month, for example, there were six escapes from closed wards and seven from open wards, about the monthly average.

However, police spokesman Warren Carmichael said that police investigators do not become involved until a missing persons report is filed. "We're not always notified promptly in the case of escapes from there, and frequently the information is incomplete or incorrect," Carmichael said.

Bruce Lindsay, of 1515 Jefferson Davis Hwy., Arlington, said he had filed several missing persons reports with Arlington police and had gone to a local newspaper and a television station seeking help in finding his wife.

Strange said that officials held Carolyn Lindsay's bed for her until Feb. 3, when they "discharged her" to free the bed for another patient. Since Carolyn Lindsay's escape, he said the institute has requested in the budget that windows be replaced.