2014 Taipei Metro attack

On 21 May 2014, at around 16:25 local time, a stabbing attack occurred aboard a Taipei Metro Bannan Line train (trainset 117/118) traveling between Longshan Temple Station in Taipei and Jiangzicui Station in New Taipei — the longest inter-station stretch in the system, giving the attacker three to five minutes to act before the train could stop. The assailant used a 30cm fruit knife to chase and attack passengers. Some passengers used umbrellas to keep distance from him while others shouted to try to discourage him. It was the first fatal attack on the Taipei subway system since it began operations in 1996.

Four passengers were killed: 26-year-old graduate student Chang Cheng-han, 28-year-old Hsieh Ching-yun, 52-year-old Pan Pi-chu, and 62-year-old Lee Tsui-yun. Pan died the day before her 53rd birthday. Twenty-four others were injured, ten of them critically, and were taken to hospitals across Taipei and New Taipei.

The attacker, identified by New Taipei Police Chief Chen Kuo-en as 21-year-old Cheng Chieh, a second-year student at Tunghai University in Taichung, was subdued by passengers, police and metro staff when the train arrived at Jiangzicui Station and was taken to a nearby police station. He told police he had wanted to do something "shocking and big" and had planned an attack since childhood, saying he moved up the timing because he had no classes that day and had grown tired of living. He stated he did not admit guilt, felt no regret, and wanted the death sentence.

Cheng was indicted on 21 July 2014 on four counts of murder and 22 counts of attempted murder. On 6 March 2015, the Taiwan New Taipei District Court found him guilty on all counts, sentencing him to death for each murder count and prison terms of five years two months to eight years for each attempted-murder count, along with lifetime deprivation of civil rights. Courts separately ordered Cheng to pay tens of millions of NT dollars in compensation to victims and their families. The Taiwan High Court upheld the death sentence, and the Supreme Court issued a final ruling upholding all previous decisions on 22 April 2016, making Cheng the first death-penalty defendant to personally appear before Taiwan's Supreme Court for a final appeal.

Justice Minister Luo Ying-shay signed Cheng's execution order on 10 May 2016, and he was executed that evening by shooting after being given general anesthesia. The 18-day gap between his final verdict and execution was described as the shortest in Taiwanese judicial history.

The attack prompted public reaction including flower tributes at Jiangzicui Station, condemnation from President Ma Ying-jeou, a joint legislative statement calling for increased security on transit systems, permanent police deployment at all Taipei MRT stations, and compensation funds set up by the Taipei Rapid Transit Corporation and city government. Comments by two legislators criticizing passengers' reactions drew public backlash. The incident also sparked debate over the death penalty.