Harry Christopher, 28, was shot five times in the back as he walked to his Buenos Aires hotel on Friday.Officers are now investigating whether his murder was the result of a bungled robbery or if he was killed as part of a drugs gangland hit.Mr Christopher, who said he was from Belfast but is from Luton, had been in the South American country for a month and had an Argentine girlfriend.He was carrying a backpack containing his laptop computer and a mobile phone when he was shot near his hotel in the Moron area.But these items were left at the scene leading police to believe robbery was less of a motive.One witness told police the killers drove up to Mr Christopher on a Gilera 125 moped and tried to grab his backpack but he fought back and began to run off with it.Detectives found 'elements...