Witnesses of its final hours raise questions about Iran's history

Source: CNN

Amid chants of "death to the dictator", an Iranian girl dressed in black stands on an overturned dustbin, waving a scarf over her head engulfed in flames.

A moment later, the video shows, she bends over to get another scarf from a friend, who will also set her on fire in front of the protesters.

The girl was 16-year-old Nika Shahkarmi from Tehran. In a video obtained and verified exclusively by CNN, just hours after these scenes were recorded on September 20, Nika disappeared. 

And after more than a week, her family found out she was dead. Iranian officials claimed that Nika's body was found on the morning of September 21 behind a courtyard. His mother did not have access to identify him until 8 days later.

A Tehran prosecutor initially said that he died after being thrown from the roof of a building and that his death that day had "no relation to the protests", but although he explicitly declared his death to be a homicide.

He didn't say that. The suspects are being investigated.  State broadcasters reported that she "fell", but provided no evidence to support the claim that it was an accident.

On Wednesday, after CNN asked the government to comment on the evidence from this investigation, an Iranian media report quoted a Tehran prosecutor as saying that Nika's death was a suicide.

The officers never explained why Nika would enter that building alone, and Nika's mother has said that she does not believe the masked man is Nika.

Her mother has said that she believes Nika was killed by officers, but officers have never said whether Nika was ever in their custody.

But dozens of videos and eyewitness accounts obtained exclusively by CNN indicate that Nika was pursued and detained by Iranian security forces that night.