One of the requirements to become a Dayton, Ohio police officer is to successfully pass the city's two-part written examination. Applicants must correctly answer 57 of 86 questions on the first part (66 percent) and 73 of 102 (72 percent) on the second part. Dayton's Civil Service Board reported that 490 candidates passed the November 2010 written test, 57 of whom were black. About 231 of the roughly 1,100 test takers were black. The U.S. Department of Justice, led by Attorney General Eric Holder, rejected the results of Dayton's Civil Service examination because not enough blacks passed. The DOJ has...