A Florida man has been arrested in the fatal shooting of up-and-coming rapper XXXTentacion. Michael Boatwright, 22, who was already in custody in an unrelated drug case, was charged with first-degree murder, the Broward County Sheriff's Office said. Boatwright is one of the two suspects who shot XXXTentacion as he left RIVA Motorsports on June 18, authorities said. The motive was believed to be robbery. InsideEdition.com's Leigh Scheps (http://twitter.com/LeighTVReporter) has more.