PARIS (AP) — The Paris prosecutor says the perpetrator of a deadly knife attack at a Paris police headquarters was likely in contact with members of an ultra-conservative reform movement of Islam.

Jean-Francois Ricard said Saturday that the civilian employee, who killed four of his colleagues, "had likely contacts with members of the Salafist movement."

Ricard said the autopsies "attest to a scene of extreme violence" in an attack that lasted seven minutes.

French prosecutors on Friday opened an investigation into Thursday's attack and said it could be terror-related.

Ricard said the knifeman had been accused of domestic violence a decade ago.

The wife of the knifeman, who was killed by police, is in custody until Monday. Ricard said she exchanged 33 text messages with her husband about religion leading up to the attack.