Anti-terror investigators have taken over the inquiry into the killing of four police employees by a colleague in Paris.
A 45-year-old IT specialist killed three police officers and an administrative worker in a knife rampage at Paris police headquarters.
A motive is unclear, with a police union initially suggesting a workplace dispute was to blame.
But investigators say new information justifies a terror probe.
The attacker was shot dead.
He converted to Islam 18 months ago, according to reports, and had recently stopped talking to female colleagues in the office.
The BBC reports that a government spokeswoman says there was no indication he had been radicalised before the attack.
BBC
