© Agence France-PresseA Palestinian demonstrator throws back a teargas canister towards Israeli forces during clashes in Hebron.
The 18-year-old was one of 15 Palestinians killed by Israeli troops on Friday as they confronted mass demonstrations at the Gaza border. Video footage appears to show Mr al-Nabi was unarmed and shot in the back by a sniper as he ran away from Israeli positions.
Images of his death have been shared around the world and both Israel and Hamas, the Islamist militant group that controls Gaza, have raced to give their own spin on the shaky mobile phone video of his final moments. The fight to define one life, and one death, has become a proxy for the broader conflict.
The Israeli military has accused Mr al-Nabi of being "an active operative of the Hamas terror organisation's military wing", the Qassam Brigades. The Israeli Defence Forces (IDF) said 10 of Friday's 16 dead had known links to terrorism and involved in violence when they were killed.
An IDF spokeswoman declined to say what evidence the army had to link Mr al-Nabi to the Qassam Brigades. "It's based on our information and it's not something we're not sure about it," she said.
But in the mourning tent in Gaza City, where neighbours and friends came to sit and drink small cups of coffee, Mr al-Nabi's family told a different story.
"He was a child just like any other child," said his father, Bahjat al-Nabi. "He was full of life, he wanted to fulfil his life." The father strongly denied his youngest son was involved in armed resistance to Israel.
"He was a kid. He was not involved in any military activity with the Qassam Brigades or anyone else," the elder Mr al-Nabi said. "This is the Israeli plan of making it look like the dead had rifles but they are murderers and the dead are the victims."
Zaid Abu Oker (19) was a friend of Mr al-Nabi and was with him at his death. He said the pair had gone to the protests to be part of the excitement of the day. Not far from the clashes, many Palestinians families had in fact brought picnics.
Mr Abu Oker said he and his friend moved close to the border to help a man who was retrieving a tyre, which Palestinian demonstrators often set on fire to roll towards Israeli soldiers.
They were racing back towards the crowds when Mr al-Nabi was shot in the back of the head. "He died straight away. He didn't even have time to say 'There is no God but Allah'," said Mr Abu Oker.
The large mourning tent was decorated with posters from the different Palestinian factions paying tribute to the shaheed, or martyr. The largest was a banner from Hamas: "The Islamic Movement of Hamas mourns its mujahid martyr." The wording implied that Mr al-Nabi had some link to Hamas but there is nothing to prove he was actually a Hamas fighter.
Human rights activists argue the issue is moot and that even if the dead men were all Hamas fighters there was no justification for killing them if they were unarmed during the protest.
"This is irrelevant unless the men were armed and endangering Israelis when killed," Elizabeth Tsurkov, a research fellow at the Forum for Regional Thinking, an Israeli think-tank.
Abdel Fattah Abd al-Nabi's death was just one of thousands in this conflict. But the controversy it has sparked reflects a much larger debate over whether Israel acts proportionally to defend its its citizens from terrorism, or wields unjustifiable violence to crush the resistance of an occupied people.
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