PHOENIX — This is part two of a five-part series looking at how illegal immigration affects U.S. border security, the criminal, health care and education systems, as well as the economy. Watch the series this week on FOX News Channel.Many police officials in states along the U.S.-Mexican border say they are fed up with the number of illegal aliens populating American prisons, many of them incarcerated for violent crimes such as murder, rape and robbery.Almost one in six inmates in Arizona, for example, is a Mexican citizen."It is a phenomenon that law enforcement recognizes as a major problem," said one undercover detective,...