Baltimore prosecutors on Monday failed for the fourth time to secure a conviction against a city police officer for the death of black detainee Freddie Gray, as a lieutenant was cleared of all charges. The acquittal of Lieutenant Brian Rice renews questions about the prospects for the remaining cases stemming from the death of Gray, who suffered a fatal neck injury in April 2015 after he was bundled into the back of a police transport van. Police union officials have called on prosecutors to drop the charges against three officers still awaiting trial in the case, which triggered protests and rioting in the mainly black city and stoked a national debate about how police treat minorities. Tensions flared anew this month with the deaths of African-American men at the hands of police in Minnesota…
