Taipei knife attacker, 27, was introverted & helpful student, showed interest in 2014 Taipei metro attack

The man who went on a rampage in central Taipei has been described as an introverted and civic-minded student while at school.

Chang Wen, 27, attacked victims with smoke bombs and a long knife on Dec. 19.

Four people died during this incident, including Chang who fell off a building to escape arrest.

While police investigations are still ongoing and Chang's motive has yet to been confirmed, Taiwanese media revealed more about the 27-year-old.

A good student

Chang studied restaurant management at Yung Ping Vocational High School in 2013.

One of Chang’s high school classmates said that while he was introverted and reclusive, he was always eager to help when others faced difficulties, ET Today reported.

The classmate remembered Chang as an obedient student, and said he was shocked by Chang’s brutal act on the evening of Dec. 19.

ET Today also reported that Chang did not miss any classes and received more than 20 commendations during his high school years.

According to his graduation remarks in 2016, Chang “demonstrated good academic performance, was civic-minded, interacted harmoniously with his schoolmates, and had no record of negative incidents.”

Unemployed and not in contact with parents

The police also revealed that Chang had been unemployed for about a year.

He was discharged from the military service two years ago for drunk-driving case.

He also had not been in contact with his family for two to three years.

At this point, he's believed to have acted alone.

Search results show his interest in 2014 metro attack

The police also found out that Chang was invested in the 2014 Taipei metro attack and appeared empathetic towards the attacker, 21-year-old Cheng Chieh.

According to ET Today, the police found search records of 2014 attack in Chang's tablet as early on as in 2024.

They suspected that Chang had been conducting extensive research on the 2014 incident since October 2025 to plan his attack.

Chang was detailed in his planning, listing the exact steps, timings and locations of the attack.

He also frequently read articles related to the 2014 attacker.

He supported those who defended the 2014 attacker, such as comments like "If Cheng Chieh knows there's someone who is willing to listen to him, maybe the tragedy would not have happened" and "Taiwanese owe justice to Cheng Chieh".

2014 metro attack

Cheng Chieh was executed in 2016, two years after he killed four people and injured 24 others in a mass stabbing on an underground train in Taipei.

He was 23 years old.

He pleaded guilty to murder and was sentenced to death after being found not to be mentally ill.

He reportedly said upon his arrest that he did not want to live because “life is full of pain and pressure”.

Following the attack, Cheng's father reportedly kneeled in public and asked for Cheng to be put to death as the crime he had committed was "unforgivable".

The 2014 metro attack shocked Taiwan, with ridership on the Taipei Metro dropping by nearly one million in the 10 days that followed.

His sentencing also sparked controversy over the death penalty and prompted mental health discussions in Taiwan back then.

Top photos from screenshot of circulating video and from Cheng Wen's Facebook