The 18-year-old killer will be sentenced at Liverpool Crown Court on Thursday.
The Home Secretary has announced there will a public inquiry into how Southport child-killer Axel Rudakubana “came to be so dangerous” and why Prevent “failed to identify the terrible risk” he posed to others.
Yvette Cooper confirmed the 18-year-old had “contact with a range of different state agencies throughout his teenage years” before carrying out his “meticulously planned rampage” at a Taylor Swift-themed dance class.
Alice da Silva Aguiar, nine; Bebe King, six; and Elsie Dot Stancombe, seven; died following the attack in The Hart Space on a small business park in the seaside town shortly before midday on July 29.
The defendant admitted their murders on Monday, as well as the attempted murders of eight other children, who cannot be named for legal reasons, class instructor Leanne Lucas and businessman John Hayes.
Ms Cooper said in a statement: “He was referred three times to the Prevent programme between December 2019 and April 2021 aged 13 and 14.
“He also had contact with the police, the courts, the Youth Justice system, social services and mental health services.
“Yet between them, those agencies failed to identify the terrible risk and danger to others that he posed.”
Announcing the public inquiry, the Home Secretary added: “Although, in line with CPS advice to preserve the integrity of the prosecution, we were constrained in what we were able to say at the time, the Home Office commissioned an urgent Prevent Learning Review during the summer into the three referrals that took place and why they were closed.
“We will publish further details this week, alongside new reforms to the Prevent programme.
“But we also need more independent answers on both Prevent and all the other agencies that came into contact with this extremely violent teenager as well as answers on how he came to be so dangerous, including through a public inquiry that can get to the truth about what happened and what needs to change.”
