Yael has found the story I was talking about. She remembers it too. I’d begun to think I was hallucinating. This is from April 2004:
Also in Paris, a 12-year-old girl coming out of a Jewish school was attacked by two men. They beat her, held her down and slashed her face with a box cutter. They carved a swastika into her face and walked away. Her parents have filed a police report.