Lt Col Bradley has been a key figure in securing Mr Mohamed's release
Lt Col Yvonne Bradley, a US Air Force reservist and a military lawyer with 20 years experience, had kept a low profile until handling the Binyam Mohamed case.
But with the British resident back from Guantanamo Bay after seven years in captivity during which he claims he was "tortured in medieval ways", it is she who has emerged as an unlikely hero of his long struggle for freedom.
Lt Col Bradley's fight to bring Mr Mohamed back home was largely unknown to the wider world until 9 February, when she flew to Britain to urge the Foreign Office to press harder for his release.
She proceeded to launch headlong into a series of meetings with Whitehall officials, and gave a number of lengthy media interviews.
By revealing that her 30-year-old Ethiopian-born client had become "very ill" as a result of a hunger strike, Lt Col Bradley appeared to spark Foreign Secretary David Miliband into action.
Two days later, the minister said he and his colleagues were working "as fast and hard as we can" with the US to secure Mr Mohamed's return.
Speaking to the BBC at the end of her week in Britain, Lt Col Bradley revealed details about her first meeting with Mr Mohamed and her immediate assumption that he was a terrorist.
"You have to realise, I'm a soldier, I was a true believer. I thought 'This guy's a terrorist'.
"I had done some heavy hitting criminal work, but was concerned, walking into a cell with someone that someone had told me was a terrorist, the worst of the worst, and I truly believed that."
The misgivings appeared to be mutual. According to an April 2006 item in the US Department of Defense (DoD) news archive, Lt Col Bradley "declared herself unqualified" to represent Mr Mohamed at the start of military commissions proceedings against him "because of a conflict of interest".
The DoD website says Mr Mohamed "asserted he did not want Bradley, or any American, to represent him in this case", and told the presiding judge: "I don't believe her being an American and a soldier - a sworn enemy of mine - will defend me. I have a problem with trusting Americans, because I've been in custody of Americans for four years."
Mohamed steps off the plane after seven years in US custody
But Lt Col Bradley had already begun to see some of the light at the end of the tunnel.
"After that first meeting with Mr Mohamed I walked out of that cell - and I was thinking: 'What are we doing?' - because if Binyam Mohamed is the worst of the worst that we are trying, we have the wrong people.
"He came over quiet and credible. I've represented many individuals before and they always say they're innocent, but Binyam wasn't like that.
"Everything he said, the way he said it, his body language. I could tell he was concerned and distanced from me because he didn't know if this was part of a disturbing game of interrogators."
She said the case against Mr Mohamed was "CIA fantasy" and that any evidence against him was only obtained through torture.
She went on: "Mr Mohammed was a new convert to Islam and didn't speak the language. There was no way anyone in Mr Mohamed's position or status was going to make his way to the top of the chain of al-Qaeda in nine months and be having dinner with some of these leaders."
Just two weeks after she first arrived in Britain to campaign for Mr Mohamed's release, Lt Col Bradley has had her wish, with her former client walking free in the country he first came to as a teenage refugee.
She maintains that for him to be labelled a terrorist was absurd.
"I look at it this way. If I detained Mr Mohamed in a garage for seven years and deprived him of all rights and called him a car, that makes him no more a car because he's detained in a garage, no more than my government can detain someone, put them in jail and label them as a terrorist, makes them a terrorist."
She is no longer the "believer" she was when she first met Mr Mohamed, quite the opposite.
"Guantanamo Bay did not contain the worst of the worst, that was part of the rhetoric. There have been prosecutors over the years who have quit, at least six publicly, there's a lot more that have gone under the radar, disappointed and demoralised."
While Mr Mohamed's own statement did not detail the alleged torture he endured, Lt Col Bradley did not skimp on any of the detail on Monday: "He had a scalpel used on his chest and on his genitals. He was severely beaten. There are also periods of times where he was hung up by his wrists - all Spanish Inquisition technique - and left there for weeks upon end."
After six years as a regular officer in the judge-advocate general's branch of the US Air Force, Lt Col Bradley worked for a further seven years for an organisation providing legal representation to death row inmates.
She now has a law practice near Philadelphia, which she put on hold while pursuing Mr Mohamed's case. She volunteered following an appeal for military lawyers to take up the cases of Guantanamo detainees in 2005.
Her job done, she can return to the US - perhaps to aid further Guantanamo inmates - "thrilled beyond what words can say".
Lt Col Bradley added: "I was able to keep a promise. There's not many promises I can keep but the last time I saw him at Guantanamo Bay I told him 'next time I see you Binyam, you'll be a free man'.
"So I'm overwhelmed, I'm thrilled that in these three years of representing him, [I can] keep at least one promise."