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 vio...