LONDON >> A British teen pleaded guilty Monday to murdering three girls and attempting to kill 10 other people in what a prosecutor said was a “meticulously planned” stabbing rampage at a Taylor Swift-themed dance class in England last summer.

The crime shocked Britain, and misinformation about the attacker sparked anti-immigrant violence across the country. The government announced it would hold an independent public inquiry into the attack, carried out by a U.K.-born teenager whose troubling fascination with violence saw him reported to authorities years before the crime.

Axel Rudakubana, 18, entered the surprise guilty pleas as jury selection had been expected to begin at the start of his trial in Liverpool Crown Court.

The July 29 stabbings led to a week of widespread rioting across parts of England and Northern Ireland after the suspect was falsely identified as an asylum-seeker who had recently arrived in Britain by boat. He was born in Wales to Rwandan parents.

Prime Minister Keir Starmer welcomed Rudakubana’s conviction, but said it was “a moment of trauma for the nation.”

“There are grave questions to answer as to how the state failed in its ultimate duty to protect these young girls,” he said. “Britain will rightly demand answers, and we will leave no stone unturned in that pursuit.”

U.K. Home Secretary Yvette Cooper said that a public inquiry would “get to the truth about what happened and what needs to change.”

She disclosed that Rudakubana had been referred to the government’s anti-extremism program, Prevent, when he was 13 and 14, and “was in contact with a range of different state agencies throughout his teenage years” — all of whom failed to spot the danger he posed.

The attack occurred on the first day of summer vacation when the little girls at the Hart Space, a sanctuary hidden behind a row of houses, were in a class to learn yoga and dance to the songs of Taylor Swift. What was supposed to be a day of joy turned to terror and heartbreak when Rudakubana, armed with a knife, intruded and began stabbing the girls and their teacher in the seaside town of Southport in northwest England.

“This was an unspeakable attack — one which left an enduring mark on our community and the nation for its savagery and senselessness,” Deputy Chief Crown Prosecutor Ursula Doyle said. “A day which should have been one of carefree innocence; of children enjoying a dance workshop and making friendship bracelets, became a scene of the darkest horror as Axel Rudakubana carried out his meticulously planned rampage.”

Prosecutors haven’t said what they believe led Rudakubana — days shy of his 18th birthday — to commit the atrocities, but Doyle said that it was clear he had a “ sickening and sustained interest in death and violence.”

Rudakubana had consistently refused to speak in court and did so once again when asked to identify himself at the start of the proceedings. But he broke his silence when he was read the 16-count indictment and asked to enter pleas, replying “guilty” to each charge.

He pleaded guilty to three counts of murder, 10 counts of attempted murder, possession of a knife and additional charges related to possessing the poison ricin and for having an al-Qaida manual.

Rudakubana faces life imprisonment when sentenced Thursday, Justice Julian Goose said.

Defense lawyer Stanley Reiz said that he would present information to the judge about Rudakubana’s mental health that may be relevant to his sentence.

The surviving victims and family members of those killed were absent in court, because they had expected to arrive Tuesday for opening statements.

Goose asked the prosecutor to apologize on his behalf that they weren’t present to hear Rudakubana plead guilty.

He pleaded guilty to murdering Alice Da Silva Aguiar, 9, Elsie Dot Stancombe, 7, and Bebe King, 6.

Eight other girls, ages 7 to 13, were wounded, along with instructor Leanne Lucas and John Hayes, who worked in a business next door and intervened. Fifteen other girls, as young as 5, were at the class but uninjured.