The car that investigators have portrayed as a killing machine used by the Washington-area snipers is getting its first thorough examination by detectives looking for clues that would explain how the men were able to roam the region and kill so many without detection. Among the items in the cluttered Chevrolet Caprice that will draw the most attention from police: a laptop computer, walkie-talkies and possible gunshot residue in a rifle port drilled in the trunk, law enforcement officials told The Sun.