Two months ago, Officer Danny Del Castillo of the Yolo County Sheriff’s Office in Northern California pulled into Lower Site, a parking lot pushed back from the winding, seldom-used Route 16. His job was to survey the area, to look around various campgrounds and rest stops and take note of anything out of the ordinary. When Del Castillo noticed the same black Nissan Maxima he had spotted the day before pulled up tightly against a row of bushes, alarms immediately went off in his head.He stepped out of his police cruiser that Oct. 14 and walked toward the car. The doors were locked and the interior was in disarray — CDs, credit cards and papers were scattered across the floor. Del Castillo ran the license plate. The car wasn’t stolen, and there were no outstanding tickets or warrants. He next called his headquarters in Woodland, 40 miles south, and the sheriff there decided the best thing to do would be to contact local authorities where the car was registered. That happened to be in Alhambra, a working-class town just northeast of downtown Los Angeles. Soon, two Alhambra police officers walked up the steps toward a small yellow duplex and rang…