CUENCA, Ecuador - Ecuadoran officials are pressing forward Monday with the trial of a Massachusetts fugitive accused of a double murder in Brockton, even as Plymouth County District Attorney Timothy J. Cruz continues to fight for his extradition to the United States. The trial comes nearly a year after a Plymouth County grand jury indicted Luis Guaman on two counts of first-degree murder for the savage beating deaths of his housemates, Maria Avelina Palaguachi and her 2-year-old son in February 2011. In Ecuador, Guaman has pleaded not guilty. The trial has set off a diplomatic clash between the two nations.