TAIPEI - Taiwan on Tuesday executed a former college student who killed four people in a random stabbing spree on a subway two years ago, in an attack which horrified the generally peaceful island.
Cheng Chieh, 23, was anaesthetised then shot three times by a firing squad at a jail outside Taipei a little before 9pm (9pm Singapore time), deputy justice minister Chen Ming-tang told reporters.
"Death was the only way to show publically that justice had been served and to relieve the sorrow and pain of victims' families," he said.
His execution surprised many, however, as it came less than three weeks after the supreme court upheld the death sentence despite last-ditch efforts by rights groups.
Among the victims of the attack in May 2014 was a man named Hsieh Ching-yun. His mother said she was "glad" Cheng had been executed.
"Losing my son is a pain that will last forever, for the rest of my life," she told the TVBS cable news network.
Prosecutors sought the death penalty for Cheng, saying psychological evaluations showed that he was not suffering from any mental disorder when he committed the crime.
Cheng, who pleaded guilty to the charges, was expelled by his university after the attack and was described by prosecutors as "anti-society, narcissistic, immature and pessimistic".
Local media said he had been obsessed with gory online games and had written horror stories.
Cheng's parents had asked for him to be sentenced to death, calling their son's actions "unforgivable".
The incident shocked Taiwan, otherwise proud of its low levels of violent crime, and resulted in several minor injuries as edgy commuters fled trains over false alarms in the following week.
There are currently 42 prisoners on death row in Taiwan, all of whom will face a firing squad when they are executed.
Hundreds of Taiwanese rallied in April (2016) to show support for retaining the death penalty after the beheading of a four-year-old girl on March 28 near a Taipei metro station.
The attack was carried out by 33-year-old man who had previously been arrested for drug-related crimes and had sought treatment for mental illness.
Taiwan resumed capital punishment in 2010 after a five-year hiatus. But executions are reserved for the most serious crimes such as aggravated murder and kidnapping.
Some politicians and rights groups have called for its abolition, but various opinion surveys show majority support for the death penalty.
In 2012 the murder of a 10-year-old boy in a playground reignited debate over the death penalty, after the suspect reportedly said he was anticipating free board and lodging in jail and would get a life sentence at most even if he were to kill two or three people.