The suburb of Courbevoie sits just west of Paris on the left bank of the Seine. It’s home to La Défense, a thicket of skyscrapers visible from the city that forms a distant, unlovely terminus to the grand axis extending from the Louvre up the Avenue des Champs-Élysées and through the Arc de Triomphe. Just a short walk from Courbevoie’s office towers, at 7:20 a.m. on Feb. 3, 2023, local police arrived at a short-term rental in a modern beige apartment block. They were responding to a domestic violence call.

Outside the apartment, the officers met the young woman who’d phoned. She told them her friend and her friend’s husband were inside. The night before, the three had been out late at a nightclub and the husband had been drinking. There had been a dispute, the woman said. Now she worried her friend was in danger. The officers knocked on the door, no one answered, and they broke it open with a battering ram.