Six months after a teenage attacker stabbed three girls to death at a children’s dance class in England, new details about his background have sparked questions about how authorities repeatedly failed to spot the threat he posed.

A British teenager who killed three young girls at a Taylor Swift-themed dance event was jailed for at least 52 years on Thursday, for an attack Prime Minister Keir Starmer called one of the most harrowing moments in Britain's history.

Axel Radakubana, who murdered three young girls and injured several more people in a mass stabbing attack at a Taylor Swift dance class in England's north west last year, is sentenced to 52 years behind bars.

Axel Rudakubana is set to be sentenced and faces a long custodial term after pleading guilty to murdering three young girls at a dance class in Southport in northwest England.

A teen has pleaded guilty to murdering three girls and wounding 10 other people in a stabbing rampage at a Taylor Swift-themed dance class in England last summer.

A British teenager on Monday pleaded guilty to charges of murdering three young girls in a knife attack in northern England in July, a crime that horrified the nation and was followed by days of nationwide rioting.

Some relatives in the public gallery were in tears. Others sat with their heads in their hands and wiped their eyes as tough security camera footage showed frightened, screaming children fleeing the scene.

Axel Rudakubana, who killed three young girls in the Southport attack, appeared to have no particular ideology but was obsessed by violence and genocide, investigators said.

After a teenager admitted murdering three girls at a dance class, Keir Starmer said people were being radicalized into violence for its own sake and terrorism laws might need to change.

Some relatives in the public gallery were in tears. Others sat with their heads in their hands and wiped their eyes as tough security camera footage showed frightened, screaming children fleeing the scene.

Axel Rudakubana, 18, will probably never be released, a judge ruled as he condemned the “extreme violence” of his knife attack on a dance class last year.