Authorities arrested a 44-year-old man Friday who they suspect set nine fires in two days south of Sierra Vista. Mario Martinez Gurrola of Mexicali, Mexico, was arrested early Friday after four vehicles - including a tractor-trailer rig - and a mobile home were torched Wednesday, according to a news release from the Cochise County Sheriff's Department. Evidence from the scenes in the communities of Hereford and Palominas, as well as similarities the fires shared, led the Sheriff's Department, Bisbee police and the fire officials to conduct an undercover operation Thursday night, the release said. That night, four more vehicles in...