Gary Donahoe learned firsthand the consequences of crossing Sheriff Joe Arpaio when the lawman was still one of Arizona's most powerful politicians.

Arpaio was launching criminal investigations against county officials eight years ago because he was upset at them over budget cuts and opposed the county's plan to build a new courthouse building. Donahoe - at the time a judge who ruled against Arpaio in the fight - got charged with bribery. The case was later thrown out, but he says his reputation was ruined.

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Now that President Donald Trump has pardoned Arpaio's conviction for disobeying another judge's order in an immigration case, Donahoe fears the lawman is going to wiggle out of his legal troubles yet again.

It was revealed Saturday, that Trump reportedly asked Attorney General Jeff Sessions earlier this year whether the Justice Department could close the case against former Arizona Sheriff Joe Arpaio, according to The Washington Post.

Critics say a pardon would remove the last chance the community has to finally call Arpaio into account for a litany of misconduct over his 24 years as sheriff. They cited Arpaio's investigations of his legal and political foes, a racial profiling case that led to his criminal conviction and his failure to adequately investigate more than 400 sex-crimes cases. Arpaio's Sheriff's office and county jail was also infamous for its treatment of prisoners, which included numerous deaths in its jail.

"Law-enforcement officials have a special responsibility to respect the rights of everyone in the United States. We should not allow anyone to believe that responsibility is diminished by this pardon," Paul Ryan said in a statement denouncing the pardon.

"The speaker does not agree with the decision," Ryan's spokesman Doug Andres said.

Some other prominent Republicans, including Arizona Senator John McCain and former Florida Governor Jeb Bush, have also criticized Trump for the controversial pardon.

Arpaio, who was booted from office last year, said Donahoe's case and other instances in which he was accused of misconduct aren't relevant to the discussion of his possible pardon.

"They have been after me for years," Arpaio said Monday. "The same people. What's new?"

Here is a look at some of Arpaio's legal issues over the years:

Investigating foes

Arpaio has a reputation for investigating officials who cross him in legal or political disputes.

Maricopa County paid $8.7 million to settle lawsuits filed by county officials who claimed Arpaio had launched criminal investigations against them on trumped-up allegations.

The disputes centered on cuts to agency budgets, a plan to build a new court complex and other issues. Donahoe, who in the end won a $1.2 million settlement, drew the sheriff's ire by disqualifying a prosecutor who was an Arpaio ally from an investigation into the construction of a court building in downtown Phoenix.

Donahoe and two county officials were charged with crimes but their cases were dismissed.

A federal grand jury conducted a nearly three-year investigation of Arpaio's office on criminal abuse-of-power allegations, specifically examining the investigative work of the sheriff's anti-public corruption squad.

But the federal investigation was closed in September 2012 without any charges being filed. He was re-elected two months later.

Racial profiling

Arpaio was convicted in July of misdemeanor contempt of court for disobeying a judge's order to stop his immigration patrols that targeted immigrants.

The conviction stems from a civil rights case in which Arpaio's officers were found to have racially profiled Latinos in his patrols.

Arpaio faced many other allegations of wrongdoing in the profiling case that didn't result in criminal charges.

He was accused of ordering some immigration patrols not based on reports of crime but rather on letters from Arizonans who complained about people with dark skin congregating in an area or speaking Spanish.

His office acknowledged throwing away or shredding some traffic-stop records during immigration patrols.

Traffic-stop videos that the sheriff's office had failed to turn over to opposing lawyers were discovered nearly two years after the trial concluded.

After some videos were discovered at the home of a sheriff's deputy who was charged in a drug case, the sheriff's office bungled a plan to gather the recordings from officers. That led the judge to voice concerns that some officers may have destroyed unflattering videos.

And Arpaio was accused of investigating the judge who ruled against him in the profiling case - an allegation the sheriff vigorously denied.

Botched investigations

Arpaio spent years trying to cultivate an image as a law enforcer who was tough on criminals.

But that reputation was undermined when his office failed to adequately investigate more than 400 sex-crimes cases, including dozens of child molestation reports, over a three-year period ending in 2007.

The sheriff, who dismissed the controversy about the botched cases as "old history," apologized in December 2011 for mishandling the cases, and his office has since said it moved to clear up the cases and taken steps to prevent the problem from happening again.

An internal review attributed the failures to understaffing and mismanagement, including hundreds of pieces of evidence intended for storage that were instead left in offices or taken home by detectives. A former supervisor says her investigators were pulled away from time to time to help with training efforts and Arpaio's immigrant-smuggling squad.

Officials agreed in 2015 to pay $3.5 million to settle a lawsuit that alleged Arpaio botched the investigation into the rape of a 13-year-old girl and failed to arrest the suspect who then went on to attack her again.

Legal costs

Maricopa County spent $141 million defending Arpaio against lawsuits.

That includes $54 million in the racial profiling case alone and $82 million in judgments, settlements and legal fees for the sheriff's office, covering issues such as lawsuits over deaths in his jails and the lawman's failed investigations of political enemies.

County officials said Arpaio has never had to pay judgments, settlement costs and legal fees in lawsuits directly connected to his official duties as sheriff.