The killer convicted of multiple knife murders and attempts to kill in a 2014 attack on the Taipei metro was executed on Tuesday evening, said Taiwan's justice authority.

Cheng Chieh, then a 21-year-old college student, randomly stabbed passengers on a subway train, killing four and injuring 22 within two minutes, on May 21, 2014. He was arrested at the scene.

Last month, Taiwan's supreme court rejected Cheng's second appeal. He had been sentenced to death in two previous trials in March and October last year.

Cheng had no mental disorder when he committed the crime, which caused panic and trauma to the victims and their families, said the justice authority.

The execution showed social justice was served, it added.

Source: XINHUA