I work as an expert witness on occasion, and always insist the called not identify which side she's on in the linguistic debate I'm supposed to referee. I can do that objectively. But what about experts who are hired from the get-go by one side? By, say, the state. In a revealing study, scientists have concluded that forensic 'experts' are prejudiced by the side that pays them. Makes sense! But this study has major implications for our court systems.