A 16-year-old girl and two boys aged 15 have admitted the manslaughter of a 36-year-old who was pronounced dead at his home a day after a “vicious” assault in a park.

The teenagers, who cannot be identified because of their age, were told a custodial term is inevitable for their parts in the unlawful killing of John Hackett in Nuneaton, Warwickshire, on April 25 last year.

The defendants pleaded guilty to manslaughter but denied murder when they were arraigned at Warwick Crown Court in Leamington Spa on Monday.

Following the pleas, prosecutor Peter Grieves-Smith told the court the not guilty pleas to murder were accepted by the Crown, and it would not seek a trial on the more serious charge.

Mr Grieves-Smith told Judge Andrew Lockhart KC, the Recorder of Coventry, that anxious consideration had been given to the issues in the case before deciding not to proceed to a trial on the murder charge.

“The family of John Hackett have been spoken to and they have understood our decision. The pleas are acceptable,” Mr Grieves-Smith said.

Judge Lockhart then told the defendants: “What that means is this – you three, having pleaded guilty, will not be tried for murder.

“But in due course you will be sentenced for the offence of manslaughter, which is unlawful killing.”

Renewing conditional bail for all three teenagers, the judge added: “You have pleaded guilty to a really serious offence here today.

“But you will get credit for that plea of guilty, which will reduce the sentence that would otherwise have been passed upon you.

In granting you bail I am giving you absolutely no indication other than you will all go to custody for this. You must prepare for that, as must your families

“Your sentence will be reduced by an appropriate margin that the judge will decide.”

The judge added: “This is plainly, as you will understand, a really important matter – not just for you but for the public as a whole.

“In granting you bail I am giving you absolutely no indication other than you will all go to custody for this. You must prepare for that, as must your families.”

Mr Grieves-Smith did not open any of the facts of the case, pending a sentencing hearing on March 15.

As the case concluded, a woman sitting to the left of the defendants, understood to be a relative of the deceased, began to sob, after saying: “They have ruined my life, they have.”

Police said Mr Hackett was pronounced dead on April 26 after emergency services were called to an address on Camp Hill Road, Nuneaton, at around 8am.

Officers said they believed the death was connected to an “altercation” which took place the previous day in the Snowhill Recreation Ground at about 6.15pm.

After the teenagers were arrested, police also confirmed they were aware of footage circulating of the altercation on social media, with officers urging people not to share it with others.

In a statement issued after the teenagers entered their pleas, Detective Chief Inspector Collette O’Keefe said: “This vicious, appalling attack left John’s family and friends heartbroken, and the wider community shocked.

“Our thoughts remain with those closest to John at this incredibly difficult time.”