By Bernd Debusmann Jr & Mike Wendling,BBC News in Washington
The protesters outside the red-brick buildings of the facility pray, discuss the news, and broadcast telephone calls with prisoners inside the jail, where hundreds of accused or convicted rioters have been held in the three years since the 6 January 2021 storming of the Capitol.
In recent months, as Donald Trump has gripped the Republican Party’s presidential nomination, the protesters have taken heart from the ex-president’s vocal public support for those who attacked Congress.
At rallies, Mr Trump plays a version of the national anthem recorded by the J6 Prison Choir – an anonymous group of prisoners thought to include several violent offenders.
On Wednesday, he posted a video of the song on his Truth Social account, describing them as “January 6th hostages” – a term he has increasingly used in reference to the rioters.
“President Trump is a man of his word,” she said. “We don’t really think everybody on January 6 was innocent of all things, but we just want them to be adequately and accurately charged and sentenced.”
When a mob of Mr Trump’s supporters breached the US Capitol to try to stop the certification of Joe Biden’s victory in the 2020 presidential election, the images of police and security officers under attack and armed rioters surging into the centre of American democracy shocked the country.
Around 140 police officers were assaulted, according to justice department figures. In total, more than 1,350 people have been arrested since then. Nearly 30 January 6 inmates are reported to be currently held in the DC jail, most of them charged with assaulting officers.
At times he has distinguished between non-violent rioters and those who “got out of control”, but his focus at campaign events largely centres on unsubstantiated claims that both he and they are victims of political persecution.
While political strategists say the focus could hurt Mr Trump electorally – particularly among independent and moderate voters he must win over to defeat Joe Biden – they see the messaging as a bid to keep his loyal base of supporters motivated.
7 January 2021: “I am outraged by the violence, lawlessness and mayhem… to those who broke the law, you will pay.” (Televised speech)
July 2021: “There was such love at that rally… the crowd was unbelievable and I mentioned the word love, the love in the air, I’ve never seen anything like it.” (Fox News interview)
January 2022: “If I run and if I win, we will treat those people from Jan 6 fairly… And if it requires pardons we will give them pardons.” (Texas rally)
May 2023: “I am inclined to pardon many of them. I can’t say for every single one because a couple of them, probably, they got out of control… And it’ll be very early on.” (CNN town hall discussion)
12 March 2024: “My first acts as your next President will be to Close the Border, DRILL, BABY, DRILL, and Free the January 6 Hostages being wrongfully imprisoned!” (Truth Social post)
16 March 2024: “You see the spirit from the hostages, and that’s what they are, is hostages. They’ve been treated terribly and very unfairly.” (Ohio rally)
3 April 2024: “January 6th hostages with President Donald J. Trump”, with a video featuring the J6 Prison Choir song (Truth Social post)
He faces four criminal indictments, including one that accuses him of conspiring to overturn the 2020 election. And embracing the 6 January defendants, observers say, bolsters his claim to supporters that the legal system is “rigged”.
“The political prisoners narrative seems to be an effort to frame the Jan 6 attack as a lawful political protest,” said Barbara McQuade, a University of Michigan law professor and author of the book Attack from Within: How Disinformation is Sabotaging America. And Mr Trump’s base want to believe in him and his narrative about the legal system, she said, even though it’s “a con”.
Several Trump supporters told the BBC that they felt sentencing of the rioters was too harsh.
Polling, however, suggests the idea that the Capitol rioters are being treated unfairly is broadly rejected by most Americans.
A Washington Post-University of Maryland survey in December 2023 found that nearly three-quarters of respondents believed punishments had either been “fair” or “not harsh enough”. And a recent survey by Associated Press-NORC Center for Public Affairs Research found two-thirds of Americans thought the riot was “very” or “extremely” violent.
Both polls showed sharp differences between Republicans and Democrats.
“Trump talking about ‘political prisoners’ activates victimhood grievance politics and connects with Republican primary voters,” he said. “But when you’re talking about swing voters – those who supported Trump in 2016 but not in 2020 – they are absolutely repulsed by January 6.”
Mr Trump has not been specific about why he believes the rioters were treated unfairly. Nor has he been specifically critical of conditions in the DC jail, which has long been the subject of complaints and lawsuits.
Some of the people given the longest 6 January sentences, for felonies such as seditious conspiracy – plotting against the government – did not directly participate in vandalism or physical violence. Instead they were prosecuted for co-ordinating attempts to stop the vote and bringing dozens of their members to the Capitol that day.
Mr Trump’s campaign did not respond to requests for comment, but a spokeswoman recently told the Washington Post: “President Trump will restore justice for all Americans who have been unfairly treated by Joe Biden’s two-tier system of justice.”
The protesters outside the DC jail agreed that a blanket pardon for all of the rioters wasn’t necessarily warranted. But they hoped that most would be freed or have their criminal records expunged.
“Our hope is that [Trump] wins and gets back in office,” said Tamara Jackson, a Texas woman whose husband Brian pleaded guilty in February to felony assault charges, and whose brother-in-law Andrew was recently sentenced to a year of weekends in jail. “Them [the detainees] coming home is obviously the goal.”
Many of Mr Trump’s political allies have echoed his support for the jailed rioters. But there has been pushback from some leading Republicans that have broken publicly with their party’s nominee.
Mr Pence oversaw proceedings in Congress to certify Joe Biden’s 2020 election win as crowds stormed the building. Some chanted “Hang Mike Pence” and he was rushed to safety as protesters broke windows before rampaging through the Senate.
“It’s just unacceptable,” he said.