The search for Christopher Dorner had three states and Mexico on alert before shifting Thursday afternoon to the snowy mountains around Big Bear Lake, about 80 miles east of Los Angeles, where police found his burned-out pickup truck.
"The question-- similar to every inquiry intro probable cause-- is whether all the facts surrounding a dog's alert, viewed through the lens of common sense, would make a reasonably prudent person think that a search would reveal contraband or evidence of a crime, " said Justice Elena Kagan.