This month marks an anniversary Hong Kong might prefer to forget. Four years ago, the government proposed a surprise new extradition law allowing suspects from the city to be tried in mainland China. The law was intended to be passed quickly, with no public consultation. The move sparked months of often violent anti-government protests and the bill was withdrawn. But it set in motion a dramatic chain of events that transformed the city. Now, as Hong Kong seeks to rebuild its international reputation after the pandemic, it needs to tackle unresolved problems relating to the crisis. The extradition bill was prompted by the murder of a young woman in Taiwan in 2018. Her boyfriend, Chan Tong-kai, is the prime suspect. He returned to Hong Kong but could not be tried in the city as the crime was committed elsewhere. There was no mechanism for him to be transferred for trial in Taiwan. Chan, if guilty, would literally get away with murder. The victim’s mother, understandably, called for justice. She described her ordeal as like “having a hole in the heart”. Hong Kong 47: ex-lawmaker says opposition plotted Legco ‘weapon of mass destruction’ The government responded with the extradition bill, to be used on a case-by-case basis. But it was not limited to Taiwan and covered all places that had no extradition agreement with Hong Kong, including the mainland. This raised long-standing fears Hong Kong people would be sent for trial under the mainland’s legal system, without fair trial guarantees. Hundreds of thousands attended peaceful protests that later morphed into civil unrest. The consequences have been far-reaching. The protests disrupted life for months. Beijing responded with a tough national security law and a new political system preserved for “patriots”. Carrie Lam Cheng Yuet-ngor, chief executive at the time, said she had no regrets. Her apology was limited to failing to better explain the bill. But the attempt to push through a “quick fix” law in the face of widely held concerns was misconceived. Lam’s successor, John Lee Ka-chiu, was security chief at the time. He has, hopefully, learned lessons from the affair. Plans to pass sensitive national security laws last year were deferred by Lee for more research. A public consultation has been promised. The process, expected this year or next, will require patience and a willingness to listen to concerns. Meanwhile, moves to heal society’s wounds are long overdue. Six thousand people were arrested over the protests. Many cases are still pending. Efforts are needed to bridge divisions and ensure those who have served their sentences are swiftly reintegrated into society. There should be research into the causes of the crisis and the government’s handling of it. Officials prefer to blame dastardly foreign powers. But the underlying issues are complex and need to be better understood. Hong Kong protests: man urged friends to make powerful nail guns, court hears Hong Kong still lacks a mechanism for the transfer of suspects to mainland China, Taiwan or Macau. Such an agreement is needed to ensure Hong Kong people arrested on the mainland are returned to the city for trial. Clear rules for transferring suspects to mainland China would also be helpful amid lingering concerns about extrajudicial rendition, which arose when booksellers from Hong Kong disappeared in 2015 only to resurface on the mainland. An agreement appeared imminent as long ago as 1998, but has not materialised. The difficulties involved have, so far, proved insurmountable. If the city is to move on, it must reflect on the events of 2019. Learning from the past will provide for a better future. The tragic irony is that the issue that started the crisis remains unresolved. Suspected killer Chan is still in Hong Kong and has not faced a murder trial. He is believed to be willing to return to Taiwan to be prosecuted. But no progress has been made. Four years ago, Lee said: “Justice is justice, and politics should not override justice.” That principle remains true for the Taiwan murder case. It also has much wider application in the new legal and political environment spawned by the extradition bill crisis.