A Hong Kong teenager's death became a magnet for conspiracies, and exposed deep problems in how the city operates

Chan Yin-lam is seen in surveillance footage from September 19, 2019 released by the Hong Kong Design Institute.

Hong Kong (CNN)The crowd recoiled as tear gas canisters rained down on them and riot police advanced up the street, carrying shields and batons.

It was August 10, 2019. Protesters had gathered outside a police station on Nathan Road, a busy shopping street in Hong Kong that had become the latest battleground in the anti-government protests that would rock the city for more than six months.
The smoke billowed forth as experienced protesters pulled masks down over their faces and scrambled to put goggles on. Many bystanders were slower to react, and took lungfuls of the stinging, choking gas as they hurried to get out of the way.
    Chan Yin-lam was one of the unlucky ones. In a video the 15-year-old posted to social media, she complained she had been out shopping and wasn't taking part in the protest.
      "I want to ask what did I do wrong?" she said into the camera, her eyes red and puffy. "I am very normal, why do I have to suffer this?"
      Like many young Hong Kongers, Chan supported the protest movement and took part in many of the large marches that eventually led the government to withdraw the extradition bill with China that kicked off the unrest. But she was never a frontline participant, her mother testified later, and largely avoided the increasingly violent action that came to characterize the protests.
      Had things worked out differently, she would likely not have played a central role in the unrest -- one of many supporters who threw their weight behind the movement but avoided direct clashes with police.
        Police fire tear gas to disperse protesters gathered outside a police station in the Tsim Sha Tsui district after taking part in a rally against a controversial extradition bill in Hong Kong on August 10, 2019.
        Six weeks later however, on the morning of September 22, Chan's naked body was found floating in the sea. She had been dead for more than 48 hours.
        The discovery sparked a maelstrom of media coverage and conspiracy theories. While police swiftly classified the case as a suicide, some in the protest movement claimed there were signs of foul play -- and even accused authorities of being involved in a cover-up..
        In the almost 12 months since she died, the controversy has not waned, fed by surveillance footage that seems to show almost all of Chan's final movements, with just enough gaps to invite speculation and conjecture.
        And far from being peripheral to the protest movement, Chan has been adopted as one of its martyrs, her face plastered over posters and flyers as other young people demanded justice on her behalf.
        On August 11 this year, after almost two weeks of hearings, a Hong Kong jury ruled the cause of Chan's death could not be ascertained.
        What should have been a private tragedy for her family has become a matter of public debate over who is to be believed: the police or the protesters. Questions about mental health support in Hong Kong, and whether institutions Chan was in contact with had failed to help her, have fallen by the wayside.
        Yet in a city divided over the government and its police force, her case is unlikely to be the last engulfed by conspiracy theories.