An Enemy Within: The Making of Najibullah Zazi

You'd think Najibullah Zazi would stand out on the high, dry plains southeast of Denver, where the earth is as flat as a starched shirt and mere wrinkles count as topography. But if heartland suburbs were ever enclaves of uniformity, that day is long gone. Aurora, Colo., is a city of people from somewhere else, a low-slung municipality of 315,000 that includes extremes of both poverty and prosperity. Aurora is vast — nearly 154 sq. mi. (400 sq km) — and dense, with a high concentration of multifamily housing units, apartment buildings, townhouses and condominiums. Those homes contain a...