Image copyright Courtesy CAN-DO Clemency Image caption Alice Marie Johnson was jailed nearly 22 years ago

A 63-year-old grandmother jailed in 1996 on a non-violent drug charge has been released from prison after she was granted clemency by President Trump.

Alice Johnson ran towards an emotional reunion with her family after leaving the prison in Pickens County, Alabama.

Her case was highlighted when Kim Kardashian West, who has lobbied for her release, met Mr Trump last week.

The White House said Johnson had been a model prisoner and worked hard to rehabilitate herself.

She was jailed alongside 15 others for taking part in a cocaine distribution ring, and convicted on charges of attempted possession of drugs and money-laundering in Tennessee.

Sorry, this Twitter post is currently unavailable.

Long battle finally over

Analysis by Jessica Lussenhop, BBC News, Washington

After four years and two presidential administrations, Alice Marie Johnson is finally going home.

I first began communicating with Ms Johnson as she waited to hear whether or not she'd been approved under President Barack Obama's Clemency Initiative in 2014. She easily met all of the criteria, she had a spotless disciplinary record and even her own warden felt that she deserved to go home.

But days before he left office, Mr Obama denied her as well as hundreds of others. She swore to me she would never put her family through this process again - the disappointment was too painful for her two daughters.

Renewed hope came in the unlikely form of a reality TV superstar - Kim Kardashian West, whom Johnson began referring to as her "war angel". Today, the long battle is finally over, though it is more a testament to the arbitrariness of the clemency process than anything else.

According to Ms Johnson's lawyer Brittany K Barnett, it was Kardashian West herself who called to deliver the news to Ms Johnson.

"Overwhelmed with emotion, Alice said it feels like she has been 'resurrected from the dead and she has her life back'."

What did the White House say?

"Ms Johnson has accepted responsibility for her past behaviour and has been a model prisoner over the past two decades," the White House said in a statement.

"Despite receiving a life sentence, Alice worked hard to rehabilitate herself in prison, and act as a mentor to her fellow inmates."

The statement added that the administration believed in being tough on crime but believed in giving a second chance to those who tried to better themselves in prison.

Image caption Are presidential pardons Trump's secret weapon?

How did Kim Kardashian get involved?

Kardashian West joined what has been a long-running campaign for Johnson's freedom, spearheaded by the clemency foundation CAN-DO, friends and family.

She was first alerted to the issue after spotting a video about the case on social media.

Kardashian West visited the White House with her lawyer, Shawn Holley, and had also linked up with Mr Trump's son-in-law and presidential adviser, Jared Kushner, who has been lobbying for prison reform.

Image copyright Reuters Image caption Kim Kardashian West at the White House last Wednesday

In a tweet shortly after the White House announcement, Kardashian West described Alice Johnson's clemency as inspirational.

Sorry, this Twitter post is currently unavailable.

A showman's flair for the dramatic

By Anthony Zurcher, BBC News, Washington

The presidential pardon power has few restrictions and scant oversight. The checks on it, such as they are, rely on norms and administrative practice without the binding force of law or constitutional strictures.

Donald Trump appears to be realising that the pardon has been a tool underutilised by his predecessors, which has the potential to grab headlines and demonstrate presidential decisiveness. With a showman's flair for the dramatic, he has turned the pardon process into a media spectacle, entertaining suggestions from celebrities and politicians, and publicly musing about who might receive a presidential benediction next.

Setting aside talk of self-pardons and the implications the more generous use of the power might have for the Russia probe, Mr Trump has - at the very least - once again rewritten how presidents ought to conduct themselves.

This president clearly believes that just because something hasn't been done that way in the past, it doesn't mean he can't do it that way now.

How do you get a presidential pardon?

The US constitution allows the president the "power to grant reprieves and pardons for offences against the United States, except in cases of impeachment".

A president can offer clemency, commutation or a full pardon, even if an individual has not been charged or convicted for federal crimes - but not at the state level.

There are currently about 9,000 clemency petitions left over from the ramp up in applications that occurred under the Obama administration, and according to University of St Thomas law professor Mark Osler, the Trump administration has done little to clear the backlog.

He adds that while he is happy for Ms Johnson and her family, there is an inherent unfairness in the way it was accomplished.

"We seem to have a dual process - one that starts with at the pardon attorney and one where people make a direct appeal to the president," he told the BBC.

"I hope he would look beyond celebrities at the hundreds and thousands of people who are more like Alice Johnson than like Scooter Libby."

At the same time, Mr Osler says that applying for clemency through the US pardon attorney is a "ridiculously bureaucratic" process and that if Mr Trump is interested in making the process faster, that's a good thing.

"I think he should ditch the long process and formalise the short one," Mr Osler told the BBC. "[It would be] far more than President Obama did in the first two years of his administration."

Other acts of clemency by Trump

The commutation of Alice Johnson's sentence is the seventh act of clemency President Trump has granted since coming into office - and the second following intervention by a celebrity. The others were:

Former Arizona sheriff Joe Arpaio , 85, had been convicted of criminal contempt but was pardoned in August 2017 while awaiting sentencing

, 85, had been convicted of criminal contempt but was while awaiting sentencing Sholom Rubashkin , owner of a kosher meat processing plant in Iowa, was convicted of fraud in 2009 and sentenced to 27 years in prison. His sentence was commuted in December 2017

, owner of a kosher meat processing plant in Iowa, was convicted of fraud in 2009 and sentenced to 27 years in prison. His Former Navy sailor Kristian Saucier was convicted in 2016 of taking photos of classified areas inside a US submarine and was pardoned in March 2018

was convicted in 2016 of taking photos of classified areas inside a US submarine and was Scooter Libby , chief of staff to former US Vice-President Dick Cheney, was convicted in 2007 of lying about leaks to the media. He was pardoned in April 2018

, chief of staff to former US Vice-President Dick Cheney, was convicted in 2007 of lying about leaks to the media. He was Boxing's first black heavyweight champ Jack Johnson was convicted in 1913 of taking his white girlfriend across state lines. He was pardoned in May 2018 after his case was raised by actor Sylvester Stallone

was convicted in 1913 of taking his white girlfriend across state lines. He was after his case was raised by actor Sylvester Stallone Conservative writer Dinesh D'Souza was convicted in 2014 of violating campaign finance laws and sentenced to five years of probation. He was pardoned in May 2018

More on Trump's pardons