Abdelhakim Dekhar, who is thought to have spent 13 years in UK after 1990s jail sentence, claimed he was a secret agent

A man who allegedly shot and seriously wounded a photographer at the French newspaper Libération was described in a psychiatric evaluation as a "voluble fantasist" and compulsive liar in thrall to his own sense of importance.

The evaluation – seen by Le Monde – has emerged amid a wealth of new details about Abdelhakim Dekhar, who is thought to have spent much of the last 13 years living unobtrusively in Britain.

The assessment was prepared by a psychiatric team in 1996 before Dekhar's trial and conviction for his role in another high-profile shooting incident, when he supplied a shotgun used by two young French anarchists during an infamous 1994 murder spree in Paris that left five people dead.

The evaluation gives a picture of Dekhar, who is suspected of causing panic in Paris this week, as an often troubled individual who spent time in care as a teenager before briefly joining the French army.

If the story of 48-year-old Dekhar is in some respects a hangover from a bygone era – a man who first came to public attention at the lingering end of a European revolutionary movement that embraced violence – it has more modern aspects too.

Not least of these is Dekhar's more recent attachment to a DIY ideology – (as French analysts have noted) – shot through with strands of narcissism, whose acts of violence appear to have had as much to do with grandiose self-invention as political grievance.

Dekhar was arrested on Wednesday after police found him in a "semi-comatose" state after an apparent suicide attempt in a car park six miles north of Paris.

It was in the mid-1990s, however, that Dekhar first came to the attention of the French authorities as the man who supplied one of the guns used by two young French radicals, Florence Rey and Audry Maupin, for which Dekhar was tried and sentenced to four years in prison. At the time of his trial for his role in the Rey-Maupin affair – which is sometimes described as France's "Bonnie and Clyde" moment – Dekhar compared himself to Nelson Mandela.

Known in radical circles as "Toumi", Dekhar was suspected by prosecutors of a much greater involvement, although it was never proved.

After prison Dekhar dropped off the map with some of his old radical colleagues believing he had gone to Algeria where his family originally came from. The reality, it has emerged, was more prosaic. Dekhar had moved to Britain where he married – twice by some accounts, once to a 27-year-old Turkish student in 2000 – and worked, at least for a while, in a restaurant in Ilford.

It was an unidentified friend and co-worker from that period who named Dekhar as a suspect in the shooting of the photographer at Libération and a gun attack on the offices of Société Générale bank.

When French police and media looked into his background after the Rey-Maupin shootings, they found long gaps and evidence of complex fantasies that he had built. The question of Dekhar's sanity was extensively investigated at the time of his trial with psychologists concluding that while he did not possess a "grain of madness" he was a voluble and compulsive fantasist.

According to his 1996 psychological report, doctors concluded: "Most of his statements take the form of a logical but fantastical construct centred around one main theme in which he is a shadowy agent, tasked with a definite political mission in service of the cause of Algerian democracy." The report, prepared by doctors Henri Grynszpan and Daniel Zagury, added he had a "constant tendency of overestimating his options … openly compar[ing] himself to Nelson Mandela…"

The report's authors addedIt said: "It is quite unrealistic to unravel right from wrong with him

… As soon as one tries to question or raise the slightest doubt over one of the points of his argument, he immediately falls back on the line of persecution and is capable of showing, on occasion, great verbal aggression."

None of this was news to his former colleagues in the radical movement. As one anonymous leader told Libération in 1996, Dekhar "behaved like a secret agent … who would not disclose his mobile number, supplied a false name for his girlfriend" and who came across as "a solitary but loudmouthed" figure "who liked to provoke meetings" he attended and disdained others in the movement for their "wishy-washy" commitment to bringing about real social change.

What is perhaps most odd is not that Dekhar, who left behind two rambling and confused letters before attempting suicide last week, popped up again as a suspect in a violent attack, but that he appears to have lived a relatively normal life in Britain in the intervening years.

If some preoccupations had not changed in that time, including his belief in his own victimisation and wider society by the elite, the precise focus had been transformed. Indeed the letters recovered last week apparently suggested his conspiratorial belief in a "fascist plot" in which Dekhar accused the media of "participating in the manipulation of the masses" and referred to western conflicts in the Middle East.

Born in 1965 in Moselle, the third child in a family of 11, his childhood was evidently troubled. Dekhar ran away from home and spent a short period in care. At 17 he joined the 9th parachute regiment based in Pamiers in the far south of France, but appears not to have served for long.

More than a decade later he would tell a judge that his military service was cut short ostensibly by problems with his eyesight but in reality because he was an agent of the Algerian secret services. He claimed to have been sent to infiltrate radical circles suspected of supporting armed Islamist terror. Nobody believed him.

If the web of dissimulation that he spun then obscured what really drove him, what he did in the intervening years in London is equally opaque.

His sister Farida Dekhar-Powell, a French teacher who lives in Essex, told journalists this week she had stopped talking to him 20 years ago after the Rey-Maupin shootings.

"He is not part of my life and that's how it stays," she said.