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.
    Protestors stand off against riot police Tsim Sha Tsui on August 10, 2019.

    Breakdown in trust

    Many news events, particularly those involving unexplained or confusing deaths, attract conspiracy theories.
    What has made Hong Kong particularly vulnerable to these since the protests broke out last year is the way trust in authorities has collapsed among certain groups, and the political divide has grown, with both sides advancing competing narratives around various events.
    "The government and police created a very ripe environment for conspiracy theories to flourish in," said Antony Dapiran, a Hong Kong-based lawyer and author of "City on Fire," a book about the unrest. "Both the police and government gave accounts of events that were so clearly at odds with the objective experiences of people who witnessed it themselves or witnessed it online."
    Violent protests involving tear gas, petrol bombs and police charges can be confusing events to follow, even for those directly involved. Hong Kong's unrest was extensively live streamed, but not everything was caught on camera -- leaving knowledge gaps in which conspiracy theories could thrive.
    Police have denied accusations of excessive use of force and rejected claims they were too quick to use tear gas and other weapons, pointing to the difficulty of controlling large, often chaotic protests over an extended period.
    While allegations of brutality were consistently leveled at authorities in the months after the protests began in June 2019, a particular series of events sent public confidence in the police into a nose-dive. In late July, officers were accused of standing by while thugs attacked protesters at a subway station in the northern town of Yuen Long. The following month, videos showed officers violently storming a subway train at Prince Edward station, beating protesters and bystanders while they pleaded for help. Separately, officers also faced allegations of sexual assault from some female protesters, both during arrests and in police stations -- accusations the force has consistently and strenuously denied.
    Before Chan's death, unfounded rumors had swirled that several people had died during the Prince Edward incident. While no bereaved families ever came forward, and there was no public record from any Hong Kong authorities to substantiate the claim, the theory soon became accepted fact for many protesters, and the station became a memorial covered in flowers.
    One man whose disappearance around that time was linked to the incident finally emerged last month. In a video posted online, he said that he'd fled to the United Kingdom two weeks before the Prince Edward protests, fearing arrest.
    "He did not come out to dispel the myth sooner because he did not want to help the police," said Paul Yip, director of the Center for Suicide Research and Prevention at Hong Kong University. "It's all very, very sad, to see this level of mistrust between the people and police."
    Dapiran blamed the Hong Kong authorities for the breakdown in trust, pointing to long delays in facing the public after key events -- such as the Yuen Long attacks -- and the way top officials pushed conspiracy theories around alleged foreign guidance of the protests.
    "All of it speaks to the absence of leadership from the government," he said. "When the authorities either abdicate their responsibility or disappear, as the government did for weeks last year, and/or there's no trust in the authorities, this creates a vacuum."
    Chan is seen in surveillance footage from September 19, 2019. At some point during the evening, Chan took off her shoes and continued walking around the HKDI campus barefoot.

    Conspiracy city

    Chan's body was discovered three weeks after the Prince Edward incide