Washington (CNN) President Donald Trump pardoned Joe Arpaio on Friday, sparing the controversial former Arizona sheriff a jail sentence after he was convicted of criminal contempt related to his hard-line tactics going after undocumented immigrants.

The move drew outcry from civil rights groups, which accuse Arpaio of violating the Constitution in his crackdown on illegal immigration.

During last year's presidential campaign, Arpaio was a vocal proponent of Trump's candidacy, and used his national notoriety to advocate for Trump's similarly aggressive stance on border security and deportations.

In a brief statement released late Friday evening, the White House praised Arpaio's career.

"Throughout his time as sheriff, Arpaio continued his life's work of protecting the public from the scourges of crime and illegal immigration," the statement read. "Sheriff Joe Arpaio is now 85 years old, and after more than 50 years of admirable service to our nation, he is (a) worthy candidate for a Presidential pardon."

"Thank you @realdonaldtrump for seeing my conviction for what it is: a political witch hunt by holdovers in the Obama justice department!," he posted.

Thank you @realdonaldtrump for seeing my conviction for what it is: a political witch hunt by holdovers in the Obama justice department! — Joe Arpaio (@RealSheriffJoe) August 26, 2017

Arpaio continued: "I am humbled and incredibly grateful to President Trump. I look fwd to putting this chapter behind me and helping to #MAGA"

He said in a Fox News interview Friday that he would hold a news conference early next week to discuss the pardon.

Trump did not consult Justice Department

The pardon is the first of Trump's presidency, though he did not follow his predecessors' practice of consulting with lawyers at the Justice Department before announcing his decision.

"This is the President's pardon," a source with knowledge of the decision said.

Under the Constitution, Trump is permitted wide leeway in issuing pardons. There are no requirements for consultation within the administration before a decision is announced.

"The President exercised his lawful authority and we respect his decision," said Ian Prior, a Justice Department spokesman.

Trump hinted at his decision earlier this week during a raucous campaign rally in Phoenix.

"So was Sheriff Joe was convicted for doing his job?" Trump queried his supporters. "I'll make a prediction. I think he's going to be just fine, OK."

Trump tweeted Friday night about his decision: "I am pleased to inform you that I have just granted a full Pardon to 85 year old American patriot Sheriff Joe Arpaio. He kept Arizona safe!"

Groups criticize decision

Arpaio, who was sheriff in Maricopa County, Arizona, until last year, was found guilty of criminal contempt last month for disregarding a court order in a racial-profiling case. His sentencing had been scheduled for October 5.

"Not only did (Arpaio) abdicate responsibility, he announced to the world and to his subordinates that he was going to continue business as usual no matter who said otherwise," US District Judge Susan Bolton wrote in a July 31 order finding him guilty

Photos: Famous pardons President Donald Trump pardoned controversial former Arizona sheriff Joe Arpaio on Friday, August 25. Arpaio was convicted of criminal contempt in July for disregarding a court order in a racial profiling case. Hide Caption 1 of 17 Photos: Famous pardons In his final days in office, President Barack Obama pardoned retired Gen. James Cartwright, former vice chairman of the US Joint Chiefs of Staff. Cartwright pleaded guilty in federal court in October 2016, admitting he lied to investigators in 2012 when questioned about whether he leaked top secret information to journalists about US efforts to sabotage Iran's nuclear program. Hide Caption 2 of 17 Photos: Famous pardons Willie "Big Mac" McCovey , a baseball Hall of Famer and former San Francisco Giants player, also received a pardon from Obama in January 2017. McCovey, now 79, was sentenced in 1996 to two years' probation and a $5,000 fine for tax evasion. Hide Caption 3 of 17 Photos: Famous pardons Obama pardoned Ian Schrager , a New York hotelier and club owner famous for the parties at his clubs Studio 54 and Palladium. Schrager was convicted of filing fake tax returns between 1977 and 1978, and was sentenced to 20 months in prison and a $20,000 fine. The 71-year-old thanked Obama, saying he had tried "to lead a good and productive life" since his conviction. Hide Caption 4 of 17 Photos: Famous pardons Before he was "Iron Man," actor Robert Downey Jr. had multiple run-ins with the law. He served one year and three months in prison for a 1996 conviction on drug and weapons charges. California Gov. Jerry Brown granted Downey a full and unconditional pardon on Christmas Eve 2015. He said Downey had "lived an honest and upright life, exhibited good moral character and conducted himself as a law-abiding citizen." Hide Caption 5 of 17 Photos: Famous pardons In late 2014, outgoing Arkansas Gov. Mike Beebe formally announced his intention to pardon his son, Kyle , who served three years of supervised probation after being convicted of possession of marijuana with intent to sell. Hide Caption 6 of 17 Photos: Famous pardons Anthony McCray is one of eight men convicted of killing their wives or girlfriends who were pardoned by Mississippi Gov. Haley Barbour. They had served in the governor's mansion, where the most well-behaved of convicts in Mississippi get to work and are commonly pardoned by the governor. Hide Caption 7 of 17 Photos: Famous pardons For Ricky Walters, aka Slick Rick, a pardon from New York Gov. David Paterson in 2008 ended his fear of being deported back to his native Britain. The hip-hop star had served six years in prison on an attempted murder and weapons charge, but faced deportation because of a federal statute to deport resident aliens convicted of violent felonies or weapons charges. Hide Caption 8 of 17 Photos: Famous pardons Billionaire investor and commodities trader Marc Rich, who violated the embargo on Iran, was pardoned by President Bill Clinton. The controversial pardon even came despite the fact that Rich fled to Switzerland and was on the FBI's most wanted list. Clinton issued about 450 pardons and commutations during his presidency. Hide Caption 9 of 17 Photos: Famous pardons Rich's wasn't the only controversial pardon issued by Clinton. Clinton also pardoned a dozen members of the nationalist terrorist group FALN, several of whom were expected to serve out their terms until their death. Hide Caption 10 of 17 Photos: Famous pardons Clinton's controversial pardon streak continued with former Rep. Mel Reynolds of Illinois, who was convicted of corruption and statutory rape of a 16-year-old campaign volunteer. Hide Caption 11 of 17 Photos: Famous pardons On his last day in office, Clinton pardoned his half-brother Roger Clinton, who was convicted of dealing cocaine. Hide Caption 12 of 17 Photos: Famous pardons President Ronald Reagan's secretary of defense secured a presidential pardon from President George H.W. Bush in 1992. Caspar Weinberger had been indicted on perjury and obstruction of justice charges related to the Iran-Contra scandal. He was one of several officials involved in the affair whom Bush pardoned. Hide Caption 13 of 17 Photos: Famous pardons All Vietnam-era draft dodgers were unconditionally pardoned by President Jimmy Carter in 1977, indemnifying hundreds of thousands who evaded or attempted to evade the draft. The blanket pardon was one of Carter's top campaign promises. Hide Caption 14 of 17 Photos: Famous pardons Carter also used his presidential power to pardon famed musician and activist Peter Yarrow, who had been convicted of taking "indecent liberties" with a 14-year-old fan. Hide Caption 15 of 17 Photos: Famous pardons President Richard Nixon avoided being indicted in the Watergate scandal after his former vice president and successor, President Gerald Ford, pardoned him for crimes he "committed or may have committed." His pardon came about a month after he resigned from office in wake of the scandal. Hide Caption 16 of 17 Photos: Famous pardons Call it good karma. Before Nixon got his own pardon, he pardoned several others, including infamous union leader Jimmy Hoffa in 1971. Hoffa had been convicted of jury tampering and fraud. But the pardon didn't keep him out of trouble, as Hoffa vanished in 1974. His body was never found. Hide Caption 17 of 17

However, civil rights groups and others pushed back against the possibility of Arpaio's pardon, and slammed the decision on Friday.

"Once again, the president has acted in support of illegal, failed immigration enforcement practices that target people of color and have been struck down by the courts," the American Civil Liberties Union wrote in a statement. "His pardon of Arpaio is a presidential endorsement of racism."

"Joe Arpaio illegally targeted and terrorized Latino families. Our community voted him out of power. Donald Trump can't change that," wrote Greg Stanton, the Democratic mayor of Phoenix, which sits in Maricopa County.

Arizona Sen. John McCain said in a statement on the pardon that "no one is above the law and the individuals entrusted with the privilege of being sworn law officers should always seek to be beyond reproach in their commitment to fairly enforcing the laws they swore to uphold."

"Mr. Arpaio was found guilty of criminal contempt for continuing to illegally profile Latinos living in Arizona based on their perceived immigration status in violation of a judge's orders," McCain said. "The President has the authority to make this pardon, but doing so at this time undermines his claim for the respect of rule of law as Mr. Arpaio has shown no remorse for his actions."

Arizona's other Republican senator, Jeff Flake, wrote on Twitter that he would have "preferred that the President honor the judicial process and let it take its course."

Regarding the Arpaio pardon, I would have preferred that the President honor the judicial process and let it take its course. — Jeff Flake (@JeffFlake) August 26, 2017

Trump has openly feuded with Flake over the past week.

Former acting Attorney General Sally Yates, whom Trump fired in January after she refused to defend his controversial Muslim travel ban, also slammed the pardon.

"With his pardon pen, POTUS reveals his own contempt for our Constitution, our courts, and our founding principles of equality and justice," Yates wrote on Twitter.

Former sheriff had questioned Obama birth record

Arpaio, who has called himself "America's toughest sheriff," was an early Trump supporter. Like Trump, he helped fuel unfounded allegations that President Barack Obama was not born in the United States. He used frequent appearances on television to establish a national platform for his views on immigration, which relied on tough enforcement measures and racial profiling.

He became known for his treatment of those he held in an outdoor jail known as "Tent City," where he made people wear pink underwear and work in chain gangs.

Trump's pardon of Arpaio is the earliest a president has pardoned someone in his first term since George H.W. Bush pardoned nine individuals on August 14, 1989.

Bill Clinton waited almost two years before issuing a pardon. George W. Bush and Barack Obama both waited about a year.