The photo arrived cracked and blurry. But the man it purported to show, dead and shirtless, was nonetheless unmistakable. He had the same high cheekbones, the same rounded countenance, the same fuzzy beard — a villainous image that anchored any number of Boko Haram terrorist videos announcing fresh horror and murder.

Could it be? Was Boko Haram leader Abubakar Shekau, who orchestrated the kidnapping of more than 200 Nigerian girls, really dead? Had the Cameroon military killed him, as it claimed the photo showed? Were the militants of Boko Haram on the run?

If only it were that simple. This is Abubakar Shekau, one of the world’s least understood mass killers. No one knows how old he is. Some say he’s 35. Others say 44. Twice he was believed dead, and twice he reemerged to usher in a broader and more diabolic campaign of killings across northern Nigeria. The idea of Abubakar Shekau, it appears, cannot be killed.

On Wednesday, the Nigerian military issued a statement saying the dead man depicted in the Cameroon military’s photograph, who looked just like Abubakar Shekau, was not in fact Abubakar Shekau. He was a double, a doppelganger, someone who has been masquerading as the leader. The alleged impostor had “been acting or posing on videos as the deceased Abubakar Shekau, the eccentric character known as leader of the group,” Defense spokesman Chris Olukolade said, according to AFP.

The “deceased” Abubakar Shekau? Without offering any proof, the military official said Shekau has long been dead, and that his appearance and name are just now a “brand name for the terrorists. … The Nigerian military remains resolute to serve justice to anyone who assumes that designation or title.” Another Nigerian official said, “the original Shekau is dead.”

Prominent Nigerian journalist Ahmad Salkid, who has gotten closer to Boko Haram than any other reporter, immediately expressed skepticism over Shekau’s reported death. “Mark my words: I have it on authority that Shekau is well & alive,” he said on Twitter. “The picture going round is NOT the person who torments us with his group.” He later added: “So Shekau has a double? So it was his double who I met during the failed attempt to negotiate an end to the plight of the [abducted Nigerian] girls? Oh, Nigeria.”

The back and forth feeds into the killer’s mystique. With Shekau, who has had a $7 million bounty on his head since 2013, it’s never been clear where fact meet his myth, whether he’s dead or alive, or whether there are many Abubakar Shekaus. It’s possible, analysts said, he has numerous doppelgangers roaming Nigeria who, if killed, afford him the opportunity to be resurrected once more and burnish his legend.

“It’s important to note, however, that Shekau may have had ‘doubles’ who appeared in some videos,” Jacob Zenn of the American think-tank Jamestown Foundation, told AFP, adding that it was plausible that one of those had been killed.

Indeed, Shekaus in some videos aren’t consistent with other Shekaus. In some videos, according to Tracking Terrorism, Shekau speaks in different cadences and has varying mannerisms. “In some cases he appears much heavier or much darker in skin color, and the posturing is very different between each man,” the think-tank wrote.

The Nigerian army can’t figure it out either. Security forces first claimed he was dead in 2009, when police in the city of Maiduguri said they had killed him in a flurry of bullets. But then he appeared in a video months later — a sequence of events that repeated last year. “Here is Shekau, Shekau, Shekau, Shekau, original,” the alleged leader chanted upon his return, grinning. “I want the whole world to know that I’m alive by the grace of Allah.”

Each time he comes back from the dead, Tracking Terrorism said, Shekau’s megalomania grows. “Shekau is a leader who is overflowing with confidence,” one article stated. “His reported death on two occasions, in 2010 and 2013 by the Nigerian military, only to resurface, reaffirmed his belief that he is protected by Allah and that no one can touch him.”

So is he still out there? Most likely yes, somewhere. Shekau wouldn’t inject himself into a pitched battle, Ryan Cummings of South Africa’s Red24 told AFP. He’s “likely” ensconced in the Sambisa Forest or the nearby mountains, far from the fighting, where he reportedly only communicates through videos and text messages.

The question of his death “may not matter much,” John Campbell of the Council on Foreign Affairs wrote. “Boko Haram is more than Abubakar Shekau, alive or dead.”

While there’s reason to agree with that — the movement did survive the death of former leader Mohammed Yusuf — the demise of Shekau would perhaps hurt Boko Haram’s aura of invincibility in northern Nigeria. And to be sure, few can match the horror delivered in Shekau’s demonic videos.

“You will now really understand the person called Shekau,” he said following an attack on Maiduguri that killed dozens. “You don’t know my madness, right? It is now that you will see the true face of my madness. I swear by Allah’s holy name that I will slaughter you. I will not be happy if I don’t personally put my knife on your necks and slit your throats. Yes! I’ll slaughter you! I’ll slaughter you! And I’ll slaughter you again and again.”