The Bourbon Street attack was part of a new pattern

SHAMSUD-Din Jabbar, a 42-year-old American citizen and military veteran from Texas, had worked as an IT specialist in the army and praised the discipline and planning that it taught him. He had also worked in real estate. He had a conviction for theft. And he had been married twice. Why he rammed a rented Ford pickup truck into a crowd of revellers on Bourbon Street in New Orleans in the early hours of January 1st, killing at least 14 and injuring 35, is mysterious and in a sense always will be.