 About this time, Robert Ambrister, a former Royal Marine and self-appointed British "agent", was captured by Jackson's army.At St. Marks a military tribunal was convened, and Ambrister and Arbuthnot were charged with aiding the Seminoles and the Spanish, inciting them to war and leading them against the United States.Ambrister threw himself on the mercy of the court, while Arbuthnot maintained his innocence, saying that he had only been engaged in legal trade.