The Guardian reports that this was a murder-suicide: the attacker (reported by authorities as being one Nordine Amrani): threw grenades and fired an automatic rifle, murdering three people, then killed himself. Prayers for the innocent victims and their families/loved ones, of course.
If you’re wondering about the name, it appears to be Mediterranean/North African in origin. Not specifically Muslim, although the Guardian is falling all over itself to try to warn of “the risks of journalists rushing to speculate in incidents such as this.” Which is actually not bad advice – this guy sounds like he might have been an apolitical druggie that went psychotic – but it makes you wonder what the Guardian knows that it isn’t telling. Or whether it itself rushing to speculate, based on the last name.