The fatal stabbing of a Muslim worshiper in a mosque in France has prompted heated criticism of government officials who did not initially treat it as a possible hate crime or show the degree of concern they had in other fatal attacks.

The victim, Aboubakar Cissé, a 21 year-old from Mali, was stabbed dozens of times Friday morning while he was praying in a mosque in La Grand-Combe, a small town in southern France, about 50 miles northwest of Avignon.

The main suspect, who filmed himself standing over the victim, was heard insulting Allah in the video, which was posted on Snapchat, French news media reported.

A local prosecutor at first suggested — wrongly, it emerged — that the killing had stemmed from a dispute between two worshipers. But on Sunday, that prosecutor, Abdelkrim Grini, said in a TV interview that the killing was being investigated as an “anti-Muslim act” or “an act with Islamophobic connotations.” Other motives are being explored, he added, including “a fascination with death, a desire to kill and a desire to be considered a serial killer.”

The suspect fled to Italy before turning himself in on Sunday at a police station in Pistoia, a small town near Florence, Cécile Gensac, the Nîmes prosecutor, said on Monday. The suspect was identified as a French national of Bosnian origin, born in 2004, who was previously unknown to the police, but nothing else about him or his views has been made public.

He has not yet been returned to France, which a prosecutor said could take weeks, or charged with a crime.