According to witnesses of the incident, Cheng stabbed everyone in his sight without saying anything, and passengers started to run toward the back of the train.

A witness said that she started to hear people screaming after the train left Longshan Temple Station, and she stood against the wall of the compartment with a few girls. She said that some middle-aged men stood in front of them to protect them.

Based on a video filmed by a witness, all passengers rushed out of the train after it arrived at Jiangzicui Station, and Cheng walked out of the train with the knife in his hand. The metro police and some passengers tackled him in the MRT station and helped police officers take him into custody.

According to Chen, three passengers who were severely injured had no vital signs after being sent to nearby hospitals, where they were later pronounced dead. Another victim was also pronounced dead five hours later at a hospital.

Cheng Wanted to Do Something Big: Police
Cheng told police that he had been planning on doing something huge that would shock society ever since he was a junior high school student, according to Chen.

Cheng told a close friend that he originally planned to commit this killing spree after he graduated from college, but last week he suddenly decided to carry out his plan on Wednesday, Chen said.

According to Chen, there is no medical record that shows that Cheng has any mental illness, and he comes from an average family that lives near Jiangzicui Station.

Chen said that during questioning, Cheng did not show any signs of regret, and he asked police officers if he would receive the death penalty for what he did.

Tunghai University, the school where Cheng is currently enrolled, said that the school was informed that Cheng stated on his Facebook page that he planned to do something big along with some angry and emotional messages in April.

The university said that the school counselors asked Cheng about his message, but he did not say much. Before any further consultations could be done, the metro killing spree took place yesterday.