At the time, it seemed like just another ugly scuffle in a long line of clashes between the police and a rag-tag group of Islamist extremists.
The setting was the Old Bailey in 2006, where four men were arrested for fighting with police and photographers as they turned out in support of a fanatic on trial for calling for British soldiers to be killed.
Among those led away in handcuffs that day, still arguing that he was within his rights to urge people to "behead those who insult Islam", was Adebolajo. Seven years on, Adebolajo, a British-born Muslim convert, is suspected as one of two men who butchered Drummer Lee Rigby in Woolwich.
The attack on the soldier, following which Adebolajo talked of an "eye for an eye" as his hands dripped with blood, came seemingly from nowhere, but the Daily Telegraph has established that the killer had been well known to the police and MI5 for years. Far from being a so-called "cleanskin", Adebolajo was a known extremist with an open MI5 file who was in plain sight all along. He preached hatred on the streets of Woolwich, where he was a familiar face to many, and turned up at volatile protests all over London.
The violent murder of Rigby was the culmination of a 12-year period of radicalisation for Adebolajo, a former Christian, which began when he was a teenager and involved several run-ins with the police, including a prison sentence for assault.
Adebolajo, 28, is the son of devout Christian Nigerian immigrants, Anthony and Ibitoye Adebolajo, who settled in Romford, east London, where Michael and his three siblings were born.
Adebolajo first became interested in Islam at the age of 16 or 17.
One school friend said: "His parents were extremely strict. They were really devout Christians. They did not let Michael or his brother and sister do anything when they were younger.
"Michael was into his football and was a Spurs supporter. All his friends were white. He was just a normal lad but as he got older he started to go off the rails.
"He was really intelligent and his parents were desperate for him to do well at school but then he got into smoking weed and also started dealing."
Another classmate said Adebolajo, known as "Narn", and his younger brother Jeremiah, known as "Jell", "changed quite dramatically" after becoming involved with drugs, "Then he started holding knives up to people's throats, getting their phones, et cetera. He'd show us the phones he'd stolen."
But "When he was about 17 he just locked himself in this room with this bloke for a few hours and when he came out he was a Muslim convert. He was spouting all sorts of stuff and said he had changed his name".
Omar Bakri Mohammed, the "Tottenham Ayatollah" thrown out of Britain when he was the leader of the now banned extremist group Al-Muhajiroun, yesterday said he had converted Adebolajo to Islam.
In Beirut, where he lives in exile, he said: "We used to have a stall on the street in London were we would talk about the meaning of life with passers-by. He stopped to speak with us and we invited him to Islam.
"Because he is a convert I can still remember him. At that time there were a lot of conflicts around the world, and in Iraq and in Afghanistan especially. We talked to him about these and he sympathised with the Muslim people, it seemed. He was in his 20s, a quiet boy who didn't ask many questions. He used to come to our open talks and speeches."
His parents tried to keep him out of trouble by moving away from Romford into a smart detached house in Saxilby, near Lincoln. His father got a job as an NHS mental health nurse near Doncasterand also represents the Royal College of Nursing as its equality officer.
His mother is understood to have had jobs as a teacher and within the NHS. But the move was too late to turn Adebolajo away from radical Islam. He moved back to London, studying at Greenwich University, where he started using the name Mujahid, or fighter for Islam.
Anjem Choudary, who took over the leadership of Al-Muhajiroun, said: "He was interested in Islam, in memorising the Koran. He disappeared about two years ago. I don't know what influences he has been under since then."
Choudary confirmed that Adebolajo was arrested outside the Old Bailey during the violent protest in 2006.
Inside the court on the day, Mizanur Rahman was being tried for soliciting murder and inciting racial hatred during a protest against the publication of a cartoon of the prophet Mohammed by a Danish newspaper.
Adebolajo was among 50 Muslims, many masked, who were attempting to interfere with the proceedings.
In 2007 he was filmed by the BBC protesting outside Paddington Green police station following the arrest of another fanatic. He is seen holding a placard which complains of a "Crusade Against Muslims". In 2008, he was charged with assault over a separate incident and spent time in jail.
He also appears to have influenced his sister Christiana, who also converted to Islam.
In the past two years he reportedly enrolled on a business course, living in a flat in Romford and spending much of his time preaching hatred on the streets and urging others to fight in Syria and Afghanistan.
In recent weeks he had been a regular presence in Woolwich, preaching outside shops.
Mayur Patel, 29, a local, said: "For the last three weeks he had been walking up and down the main street shouting and preaching. It was an obvious sign there was a madman walking around."
A 51-year-old who gave his name as Tom said: "I saw him on his own outside the pound shop last week shouting about jihad. He was aggressive, trying to draw people's attention to him."
Yesterday police searched five London addresses and the Adebolajo home in Lincolnshire. A 29-year-old man and a 29-year-old woman were arrested on suspicion of conspiracy to murder.
Members of Adebolajo's family were either taken from their homes by police or left of their own accord yesterday. His sister Blessing, 32, was taken away from her home in Romford, which she is thought to have shared with Adebolajo, before a police search team moved in.