It's been five days since federal prosecutors announced they closed the criminal investigation into Maricopa County Sheriff Joe Arpaio and his office, and protesters are demanding answers from the US Attorney's Office.

His critics want to know why.

The press release was issued Friday at 5 p.m., just before a holiday weekend. Now Tuesday, they're still not talking about why the investigation is closed.

Protesters from the Citizens for a Better Arizona were turned away from the US Attorneys Office Tuesday morning. The group is demanding answers after the feds dropped their abuse of power investigation into Sheriff Arpaio.

"You guys are a bunch of cowards, you all should be ashamed of yourself for working for this department!" yelled Randy Parraz of Citizens for a Better Arizona.

In a letter sent to County Attorney Bill Montgomery, federal prosecutors said they have a higher burden of proof, and didn't think they had a strong enough case against Arpaio.

"This is a decision based on the facts and the law," Paul Charlton, a former US Attorney, told FOX 10.

Charlton has worked for one of the county supervisors considered Arpaio's victim. Still, he trusts the decision.

"It wasn't a fault of evidence, it wasn't that there wasn't any evidence, it was that there was not sufficient evidence to prove this case beyond a reasonable doubt and with a reasonable likelihood of conviction."

Charlton also points out the letter didn't clear Arpaio of anything, just closed the investigation.

"There was wrongdoing here. There was a violation of the law. The justice department has said it didn't rise to the level of a provable crime, but that doesn't mean Joe Arpaio's days in court are over."

This investigation was a criminal investigation. There is still an ongoing civil matter involving allegations of racial profiling.

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