Arpaio's Web site claims he "continues to reduce crime with hard-hitting enforcement methods." It also says that his office has "solved several high-profile murder cases, including nine child murders."
The department's performance can be assessed by the percentage of crimes that are solved or cleared per year. Most crimes are cleared either by an arrest or by an "exception," such as where the perpetrator is known to police, but can no longer be apprehended. Clearance by "exception" is supposed to be exceptional. But, in Maricopa County, that's not the case.
In 2006, 75 percent of cases were closed on the basis of exception as opposed to by arrest, according to the Goldwater Institute. In 2008, the Goldwater Institute also reports that only 18 percent of cases were cleared as a result of an arrest, while 82 percent were cleared as a result of exception.
"You know that was a criteria that was not an official type of statistic. That's somewhat how we look at it. It's not an official type statistic...it's just something that our policy is," he said.
"Those figures are misleading because we do solve over 50 percent of our homicides, but it's how you look at it whether it was a husband-wife murder..." Arpaio continued.
Pressed to explain why 82 percent of cases were declared cleared by exception, and if his department was writing cases off instead of reducing crime, Arpaio said his department clears more than 18 percent of cases by arrest.
"We do clear a higher percentage of that. I know that. We clear many, many cases -- not 18 percent," he said.
"Nightline" contacted the Sheriff's department again after the interview and was told that of 7,346 crimes -- only 944 had been cleared by arrest -- which amounts to only 15 percent. The remaining 85 percent were deemed inactive, unfounded or cleared by exception.
We asked Arpaio to address allegations that he's reducing crime on paper, but not in practice. "It's a bad allegation..." he said. "We solve over 50 percent of our murders. I'll put that against any other law enforcement. You're quoting exception and how the FBI clears cases...I got the facts. We have cleared over 50 percent of murders!"
Arpaio argues that he makes prisoners' jail time so painful that they never want to come back. To deal with overflow, around 1,200 inmates are held in "Tent City," the infamous outdoor extension of the jail facility. In blistering Arizona heat, no air conditioning and meticulously rationed meals.
"This is disgusting," one inmate told "Nightline" during a tour of the facility. "I don't care who you are, you should never treat a human being like this. It's wrong. The food we eat is disgusting. We get food that's donated and we don't even know how old it is let alone if it's any good any more. Some people get sick from it. It's more like a concentration camp than anything else."
Arpaio is unapologetic about inmate treatment. "They get 2,500 calories," he said. "It was 3,000 and we knocked it down to 2,500. How many people are on 2,500 calories? I'm not even on 2,500!"
Arpaio then acknowledged that he might consume 2,500 calories per day. "Okay forget about me," he said. "I have to get on a diet. I just gained some weight."