The rate of repeat offenders is on the rise for the same reason the crime rate is on the rise. Sheriff Joe is a publicity hound but there is no denying that he is a tough Sheriff and he gives the people of Maricopa what they want in a Sheriff.
Also I would say that the conditions of the detention facility are not a major deterant to crime. Most criminals commit crime with the mind set of not being caught. If the conditions were a major factor crime would be going down in states like texas that have some of the toughest penalties in the nation. The fact is as the city grow so does the crime rate and when you are a border state with high illegal immigration then it rises faster. Not because illegal immigrants are criminals (they are) and causing more crime. But when you had to the population of poverty in a county or city the rates will rise. Thats just the way it works.