PARIS — An 85-year-old woman who as a child narrowly escaped France’s most notorious wartime roundup of Jews has been murdered in Paris, and the authorities are calling it a hate crime.

The body of the woman, Mireille Knoll, was found on Friday in her apartment in the city’s working-class 11th Arrondissement. She had been stabbed to death, and her body was partly burned after her attackers apparently tried to set fire to the apartment.

The Paris prosecutor’s office said on Monday that Ms. Knoll had been killed because of the “membership, real or supposed, of the victim of a particular religion” — a roundabout way of saying she was killed because she was Jewish.

Ms. Knoll was a child in Paris when, in the summer of 1942, the French police, cooperating with the Germans, rounded up thousands of the city’s Jews, stuffing them into a cycling stadium, the Vélodrome d’Hiver. Virtually all were subsequently murdered at Auschwitz.