BALTIMORE — The parents of Freddie Gray reached a tentative $6.4 million settlement with the city of Baltimore, nearly five months after their 25-year-old son was critically injured in police custody, sparking days of protests and rioting.The deal, announced today, appeared to be among the largest settlements in police death cases in recent years and happened just days before a judge is set to decide whether to move a trial for six officers charged in Gray’s death.Gray’s spine was injured April 12 in the …