A Japanese man dubbed the “Twitter killer” was sentenced to death by a Tokyo court Tuesday for murdering and dismembering nine people he met on the social media platform.

Takahiro Shiraishi, 30, admitted killing and butchering his young victims, all but one of whom were women.

His lawyers had argued he should receive a prison sentence rather than be executed because his victims, aged between 15 and 26, expressed suicidal thoughts on social media and so had consented to die.

But a judge dismissed that argument and handed down the death penalty over the 2017 crimes, which he called “cunning and cruel,” public broadcaster NHK said.

“None of the nine victims consented to be killed, including silent consent,” NHK quoted the judge as saying.

“It is extremely grave that the lives of nine young people were taken away. The dignity of the victims was trampled upon.”

The judge added that the case, which prompted calls for tighter control on social networks, “provoked great anxiety in society, because social networks are so commonly used.”

The grisly murders attracted international attention, and the case has been followed closely in Japan, with 435 people reportedly turning up to secure one of 16 available public seats.

When asked if the verdict was audible, Shiraishi, wearing a white mask, stood still and only said: “I understood.”

Family members of the victims have spoken emotionally of their continued pain over the case, with the brother of a 25-year-old woman killed by Shiraishi saying his “heart died” when he heard the murderer’s testimony.

“It didn’t sound at all like he regretted it… It felt like I was being hurt with a sharp knife over and over again.”

The woman’s father said in court last month he “will never forgive Shiraishi even if he dies”, local media reported at the time.

“Even now, when I see a woman of my daughter’s age, I mistake her for my daughter. This pain will never go away. Give her back to me!” he said.