Prosecutors in Paris are investigating a knife attack that killed four people at police headquarters as a potential act of terrorism.
Three police officers and an administrative worker were killed by the knifeman, who was subsequently shot dead at the scene.
The prosecutors’ office has said investigators looking into the case found elements that led to a probe for multiple murders “in relation with a terrorist enterprise”.
Working to determine the motive behind the violence, police scoured the 45-year-old attacker's computer and mobile phone and interviewed his wife and witnesses.
Authorities said the assailant was an IT administrator who had worked for the Paris force’s intelligence unit since 2003. He converted to Islam 18 months ago.
Officials said earlier that the man did not have a history of psychiatric problems and investigators did not have evidence at that point indicating he had been radicalised by extremists.
The incident happened at lunchtime on October 3 at the capital’s police headquarters just across from the Notre Dame cathedral.
The area was sealed off and the country’s president Emmanuel Macron visited the scene, along with prime minister Edouard Philippe and interior minister Christophe Castanter.
London’s Metropolitan Police Commissioner Cressida Dick said: “On behalf of all the men and women of the Metropolitan Police Service, I want to express our deepest sympathy to our colleagues in Paris.
“We are shocked and saddened to hear of this act of appalling and senseless violence.”