Support WBUREliminating Police Bias When Handling Drug-Sniffing DogsPlay05:28Download AudioMartin KasteNovember 20, 2017 ShareOfficer Darrell Lobe of the Bothell, Wash. police department "proofs" a hidden-drugs test at the start of a K9 certification. The location of drugs in the vehicles was determined by rolling a die to prevent bias. (NPR)