Paris: A Muslim convert suspected of stabbing a French soldier in a religiously motivated attack was placed under formal investigation on Friday over an apparent act of terrorism, prosecutors said, a move that could lead to a trial.
Alexandre Dhaussy, 22, was brought before an anti-terrorism judge who determined there was enough evidence of what prosecutors called a terror-related assassination attempt to proceed with an investigation.
Under French law, a formal investigation means there exists "serious or consistent evidence" of a suspect's probable implication in a crime and is an important step towards a trial.
France has been on heightened security alert since January , when its military intervened in Mali to help repel al Qaeda-linked Islamist rebels.
France has been on heightened security alert since January 2013, when its military intervened in Mali to help repel al Qaeda-linked Islamist rebels who had been seized control over the north of the former French colony.
The May 25 attack on the soldier in Paris reinforced government fears that so-called "lone wolf", self-radicalised assailants could commit revenge attacks on French soil.
Fingerprints and surveillance footage led police to Dhaussy, whom they say may have been influenced by an attack in London three days before in which two men chanting Islamist slogans hacked a British soldier to death in the street.
Dhaussy, who was arrested on Wednesday, is suspected of stabbing the soldier in the neck while he was patrolling a Paris business district, and then fleeing the scene.
The soldier survived and has been released from hospital.
Police have said Dhaussy - who as a minor had a petty crime record and converted to Islam as an adult - was known to them for recent incidents that pointed to radicalisation, but he had not been considered dangerous.
In 2012 police stopped him after he acted suspiciously and did not want to wait for a bus alongside women. In 2011 he refused a job that would have involved working alongside women.
Le Monde daily reported that police had signalled concerns about Dhaussy in a note to the DCRI domestic intelligence service, but that the DCRI never followed up on the report.
Interior Minister Manuel Valls defended both agencies' work to French media, saying there were "many such fundamentalists" in France but not all merited surveillance by security services.
High on the list of French security concerns are young men from disadvantaged neighbourhoods who are radicalised by certain Islamist preachers or websites and turn to violence.
In March 2012, one such man, Mohamed Merah, killed four Jews and three soldiers in and around the southern city of Toulouse before being shot dead by police. The rampage represented the worst terror attack on French soil since 1995.