SIERRA VISTA — With increased notice being paid to border security since the killing of a Cochise County rancher last month, it is important that local and state lawmakers get a commitment from the federal goverment to provide additional security along Arizona’s border with Mexico, the county’s sheriff said Monday. “While we have the nation’s attention, it’s important that we strike now,” Larry Dever said. The killing of Robert Krentz, presumably by an illegal immigrant, “has put an exclamation point on the problems that we face and have faced down there for some time,” the sheriff said during a telephone...