After Promising Youth, London Attacker Became Troubled Loner

LONDON — On the final night of a troubled, disjointed life that began in the affluent English countryside and ended in a deadly rampage on the streets of London, Khalid Masood returned to his roots.He had lived for years in the British Midlands, known to neighbors as a devoted gardener but otherwise all but invisible, an urban ghost who left few traces after a series of criminal convictions and a mysterious trip to Saudi Arabia.Yet on Tuesday night, at age of 52, Masood rented a car and drove to southeast England, where he was raised.