We had agreed that preparations would take at least a week and a half. So it wasn't until a windy afternoon toward the end of March that I headed north to Westminster. I pushed through the double glass doors of Maryland State Police Barracks "G" and signed in at the desk. The corporal handed me a pass that I pinned to my jacket, then I rode the elevator to the second floor. Each door down the brightly-lit hallway had an identifying sign protruding from the transom that reminded me of a miniature street sign. Interview One, Two, and Three, Storage, Records, Properties, Holding One and Two, and directly across the hall, C.I.U. From the spacing of the doorways, it looked like the Criminal Investigations Unit had been allotted a generous slice of floor space. C.I.U. was stenciled across the pebbled glass in black rimmed with gold. I opened the door and stepped inside. Two rows of pale blue partitions formed a wide central aisle that stretched to the back wall. The room was freshly-painted in a creamy yellow, and the slate gray wall-to-wall was new.