Despite reports to the contrary, he does not appear to have fought, or received training, abroad. Although still under surveillance, he was regarded by French internal security as a low risk "has-been".
Said, though older, has always been in Cherif's shadow. He had never been seen as any sort of threat.
All French security's efforts have been focused in recent months - with some success - on preventing domestic acts of terror by jihadis returning from Iraq and Syria. These men, mostly in their teens or twenties, are often recent recruits to the cause and, in some cases, recent converts. Chérif, and therefore Said, were overlooked as they belonged to a previous generation of home-grown extremists.
Cherif, according to Vincent Ollivier, his former lawyer, went into his first prison term in 2006 as confused kid and emerged as a physically stronger radical. One of the Islamists with whom he consorted in jail was Salim Benghalem, now regarded by the US as a principal organiser of Isis in Syria.
Was the attack an Isis operation? French security officials - perhaps covering their embarrassment - believe it was more likely a freelance attack, inspired by Isis, but not directly ordered or controlled from the Middle East. They were describing the brother's yesterday as a "family terrorist cell".
Watch: In 2005 Cherif Kouachi wanted to be a rapper
The Charlie Hebdo assault was a bizarre mixture of chillingly professional and chaotic. The gunmen were calm, ruthless and heavily armed. On the other hand, they were extraordinarily feckless. They were rapidly identified as suspects when Cherif left his identity card in the car they crashed a mile from the massacre.
They had initially tried to storm the wrong building. And yesterday, rather than lying low, two men identified as the brothers pulled into a rural petrol station in the Aisne and ordered their car to be filled at gunpoint.
The Kouachis do not have the typical profile of converts to radical Islam. Aged 4 and 2, they were placed in a children's home in Rennes before being fostered by a local family who had converted to Islam.
Cherif qualified as a sports teacher and worked briefly in Rennes - a 2005 Facebook post shows him rapping. The brothers moved to Paris and then the northern suburb where they became involved in petty theft and drug dealing. Ollivier remembers him in his early twenties as "an apprentice loser in a baseball hat".
This image obtained by AFP from a French police source shows a reproduction of the ID card of Said Kouachi found in the car left by the two suspects. Photo / AFP
"He smoked, drank, wore no beard and had girlfriends," the lawyer said. "He was a confused kid who did not know what to do with his life and then, overnight, met people who persuade him that he was important."
Cherif was first radicalised, said Ollivier, by the US-led invasion of Iraq. He was especially outraged by the images of mistreatment at Abu Graib prison. Even then, Ollivier said, Chérif recruited others but did not go himself, knowing that few foreign recruits lived long. He was convicted in 2006 of aiding and abetting a terrorist organisation and sentenced to 18 months in prison - a term which he had already served on remand.
In 2010, he was arrested and served another six months on remand on suspicion of belonging to jihadi group trying to spring a leader from jail. He was re-released without trial after persuading investigators he had joined the group - and travelled to an alleged Auvergne training camp - only to "play football".
Cherif appears then to have dropped off the security services' radar. Said scarcely merited a blip on their screens.
Authorities believe the Charlie Hebdo attack had been long planned by Cherif. If so, why? What turned the jihadi "has-been" into a brutal killer? Was he guided from the Middle East? No answers are likely unless the brothers are captured alive.
An 18-year-old man initially believed to have driven the killers' car gave himself up to police yesterday. Mourad Hamyd - Cherif's wife's brother - told investigators he was at school in Charleville-Mezieres, 290km from Paris on Wednesday morning. He is no longer regarded as a suspect.
- The Independent
