President Donald Trump has pledged to chase what he called the 'bad hombres' out of America. One of the organisations the President is targeting is the notorious Mara Salvatrucha gang, better known as MS-13 whose members deal in drugs, human smuggling and underage prostitution. They aggressively recruit young Latino immigrants in U.S. cities and suburban communities and have recently been responsible for a number of shockingly brutal murders, including the killing of two teenage girls with machetes and baseball bats. Lucy Ash travels to Long Island in New York and to Maryland to investigate. She asks what impact such crimes have on the heated debate about illegal border crossings and she asks if tougher immigration policies will really make America safe again.