PHOENIX, Ariz. Federal authorities say members of a violent Mexican gang are using the Arizona border as a corridor to the country. In the past year, Border Patrol agents have arrested about ten members of Mara Salvatrucha -- a notorious international street gang in Mexico. Yet according to federal and local law enforcement officials, the gang members don't appear to stay in the state. The gang is commonly known as M-S-13 and has been linked to murders from Honduras to Los Angeles to Virginia. Original Mara Salvatrucha members were guerrilla fighters who fled the Salvadoran civil war in the 1980s....