A former employee at a care home for disabled people admitted to killing 19 patients in one of postwar Japan's worst mass killings. The attack shocked the country and sparked a debate about the stigma the disabled face.

A court in Japan on Monday sentenced a man to death by hanging for the murder of 19 people at a care center for disabled people.

During the trial, Satoshi Uematsu did not deny carying out the killings and said he had "no regrets." His lawyers had entered a not guilty plea. They argued he was suffering from a "mental disorder" due to drug use.

Details of the verdict

However, presiding judge Kiyoshi Aonuma ruled the defendant was mentally competent and that there was "no room for leniency."

"The lives of 19 people were taken away. This is profoundly grave," he told the court. "We considered the accused didn't have a previous record and we made a careful consideration, but we demand the death penalty."

Before the verdict, Uematsu had said he would not appeal. 

Read more: Amnesty International reports global drop in executions

What happened in the attack?

The 30 year-old once worked at a care center for people with mental disablities southwest of Tokyo. 

Uematsu admitted stabbing to death 19 disabled people and injuring 24 others at the Yamayuri-en residential buildings in July 2016. Many of the victims were killed as they slept.

He reportedly told the court the victims were "a burden to society" and killing them would be good for society.

The attack was one of the deadliest in Japan since World War II.

He said disabled people are the cause of unhappiness.