(Ramsey, Co., MN)  —  Charges are now being filed in the murder investigation connected to the raid that killed Amir Locke.  Ramsey County prosecutors are filing second-degree murder charges against 17-year-old Mekhi  [[ meh-KY ]]  Speed.  Speed was arrested Monday in Winona.  He was wanted in connection to the murder of Otis Elder in St. Paul in January.  Minneapolis police served a search warrant last week for three apartments in Bolero Flats, one belonging to Speed and another where Amir Locke was found asleep.