Ruth Paine, a woman of deep Quaker faith who in 1963 opened her modest ranch-style house in a Dallas suburb to Marina Oswald and, to a lesser extent, her husband, Lee Harvey Oswald, in the months before he was arrested and charged with killing President John F. Kennedy, died on Aug. 31 in Santa Rosa, Calif. She was 92.

Her death, in a Quaker retirement village, was confirmed by her son, Chris Paine.

Ms. Paine’s knowledge of the Oswalds made her a noteworthy witness during the Warren Commission’s investigation into the assassination. The panel concluded that Mr. Oswald had acted alone when he fired shots at President Kennedy on Nov. 22, 1963, from an open window on the sixth floor of the Texas School Book Depository in Dallas. Gov. John B. Connally of Texas, who had been in the limousine with President Kennedy and their wives, was wounded in the shooting but recovered.

“She knew more about the Oswalds’ movements and moods in the months prior to the assassination than anyone else did,” said Thomas Mallon, who wrote about Ms. Paine and the Oswalds for an article in The New Yorker in 2001, which he expanded into a book, “Mrs. Paine’s Garage: And the Murder of John F. Kennedy” (2002).

Ms. Paine, who was living in Irving, a suburb of Dallas, met the Oswalds at a party in Highland Park, in Dallas County, on Feb. 22, 1963. She had been looking forward to the gathering because she was told that Mr. Oswald, a young American who had spent time in the Soviet Union, would be there with his Soviet-born wife. The party offered Ms. Paine a chance to speak to someone in Russian, which she had been studying through Berlitz and other language courses on and off for several years.

Mr. Oswald talked about his time in the Soviet Union, where he had defected in 1959, and where he had married Marina Nikolayevna Prusakova before returning to the United States in 1962.

“He really enjoyed being the center of attention,” Ms. Paine told Mr. Mallon, adding that she was unimpressed and gravitated instead to Mrs. Oswald. “I wanted to see if I could talk with her, if we could communicate.”