US President Joe Biden has granted his son, Hunter Biden, a full and unconditional pardon just weeks before he is due to leave office.
The Democrat had been facing a swirl of speculation over whether he would grant clemency to his second son, who was convicted of three federal gun felonies and tax crimes earlier this year.
Hunter Biden is a recovering drug addict who has been a target of Republican conspiracies since his father came to office.
Donald Trump and his allies have sought to use the 54-year-old's troubled past and business dealings as a political weapon against Joe Biden, particularly when he was running for a second term in office.
The White House has repeatedly said the president would not intervene in Hunter Biden's court cases and in June, when the president was still the Democratic presidential candidate, he'd confirmed his decision to remain impartial.
"I am not going to do anything," he said when asked about his son on the sidelines of a G7 summit.
But Mr Biden appears to have had a change of heart while spending Thanksgiving with his family, including his son, over the weekend.
In a statement granting clemency, the president said he believed there was a political element to Hunter Biden's convictions.
"There has been an effort to break Hunter — who has been five and a half years sober, even in the face of unrelenting attacks and selective prosecution," he said.
"In trying to break Hunter, they've tried to break me — and there's no reason to believe it will stop here. Enough is enough."
This is what we know about the presidential pardon system and how it has historically been used.
America's pardon system
All US presidents have the power to issue pardons at any time during their term.
The special measure is established by the US constitution and is quite broad, allowing the commander-in-chief to grant clemency to anyone for any federal crime.
Presidents can be lobbied directly to grant clemency. They also receive recommendations from a pardon attorney operating out of the US Justice Department (DOJ), which receives and reviews applications for clemency.
Mr Biden has previously acted on the DOJ's advice to grant pardons, used them to facilitate prisoner exchanges with other countries and to grant clemency to more than 6,500 people convicted of possessing marijuana.
But exercising the power can have considerable political ramifications, especially when the cases involve controversial figures or scandalous crimes.
This is why some presidents typically wait until their final weeks in office to grant a pardon.
Other clemency decisions have previously been made around Thanksgiving or Christmas, according to political experts.
What is Hunter Biden being pardoned for?
Hunter Biden has been a focus of intense scrutiny from Republicans since his father became president.
One of their biggest lines of attack against him is an unfounded theory that he was involved in a conspiracy with Ukraine when his father was vice-president.
The 54-year-old has been public about his battles with drug addiction and was convicted of two separate crimes earlier this year.
In the first case, a jury in his home state of Delaware found Hunter guilty of lying on a gun purchase form and unlawfully possessing a weapon.
The other revolves around a federal tax case in California, where Hunter Biden has pleaded guilty to nine charges, including tax evasion and filing fraudulent returns.
Hunter Biden said he would not take his father's decision to grant him clemency for granted.
"I have admitted and taken responsibility for my mistakes during the darkest days of my addiction — mistakes that have been exploited to publicly humiliate and shame me and my family for political sport," Hunter Biden said in a statement.
"I will never take the clemency I have been given today for granted and will devote the life I have rebuilt to helping those who are still sick and suffering."
Why did Joe Biden pardon his son?
In granting his son clemency, Joe Biden said he believed the charges against Hunter Biden were politically motivated and designed to hurt him.
He acknowledged that he had pledged not to interfere with the Justice Department's decision-making, but had watched his son "being selectively, and unfairly, prosecuted".
It is his view that "Hunter was treated differently" and that most people are not prosecuted for the crimes that his son has been convicted of.
"The charges in his cases came about only after several of my political opponents in Congress instigated them to attack me and oppose my election," Mr Biden said in the statement.
"No reasonable person who looks at the facts of Hunter's cases can reach any other conclusion than Hunter was singled out only because he is my son — and that is wrong."
Last year, the Republican-controlled House of Representatives ordered an impeachment inquiry into Biden, claiming he financially benefited from Hunter's business dealings in Ukraine and China.
No evidence of wrongdoing was ever found, and Hunter refused to testify in the inquiry, claiming it was a politically motivated witch-hunt.
"There is no evidence to support the allegations that my father was financially involved in my business, because it did not happen," Hunter said at the time.
In August, the committee claimed the president had committed impeachable offences, while stopping short of recommending impeachment itself.
Why didn't Joe Biden wait for a famous 'midnight pardon'?
Biden has just 49 days in office before his successor, Donald Trump, is sworn into office and returns to the White House.
The 82-year-old's political career will then officially be over, which gives him some leeway to make some decisions without fear of being punished at the ballot box later.
In an unofficial practice known as "midnight pardons", most presidents wait until their final day in office to grant clemency to controversial figures.
Bill Clinton signed a slew of pardons in the last hours of his time in the White House, including one for his half-brother.
Roger Clinton Jr had a 1985 cocaine possession and drug-trafficking conviction wiped off his criminal record.
And in 2008, George W Bush commuted the sentence of Lewis "Scooter" Libby, a White House aide who was found guilty of perjury, obstruction of justice and making false statements in relation to the unauthorised disclosure of a CIA agent's identity.
So why did Biden decide to endure weeks of questioning and criticism rather than waiting for the final hours of his presidency?
Hunter was due to face separate sentencing hearings for his crimes in mid-December.
He could have faced up to 17 years in a federal prison for his federal tax case alone.
But a "full and unconditional pardon" wipes his slate clean, and means the hearings won't go ahead.
