Axel Rudakubana, 18, on Monday admitted carrying out the killings in the town of Southport, an atrocity that was followed by days of rioting across the United Kingdom.
He also pleaded guilty to 10 charges of attempted murder relating to the attack, as well as to producing the deadly poison ricin and possessing an al-Qaeda training manual.
A prosecutor started to outline what happened on the day of the three girls' murders last year. (AP PHOTO)
At his sentencing at Liverpool Crown Court, Rudakubana repeatedly interrupted prosecutor Deanna Heer, shouting from the dock: "I need to speak to a paramedic, I feel ill."
His lawyer Stan Reiz said that Rudakubana was suffering from chest pains.
After Judge Julian Goose refused to adjourn the sentencing, Rudakubana shouted "don't continue," prompting the judge to ask him to be removed.
Someone shouted "coward" from the public gallery as he left.
Before his outburst, prosecutor Deena Heer had started to outline what had happened on the day of the murders in July last year, saying he was not inspired by any political or religious ideology.
"His only purpose was to kill and he targeted the youngest, most vulnerable in order to spread the greatest level of fear and outrage, which he succeeded in doing." she said.
"Whilst under arrest at the police station after the incident, Axel Rudakubana was heard to say 'It's a good thing those children are dead ... I'm so glad ... so happy'."
