The old wood cabin sat alone, surrounded by trees and darkness. The shades were drawn, and a dog lay motionless on the front porch. A thin stream of smoke flowed out of the chimney and headed west, across the rural Maryland countryside toward Washington, D.C. Inside, a man sat silently in front of the fireplace, shoving stacks of paper into the hot flames.
The papers were the product of months of tedious and meticulous work. Each sheet represented hour upon hour of surveillance notes, in-depth subject profiles, and maps of neighborhoods throughout the D.C. metropolitan area. He knew when the police patrolled, when the newspapers...