Sheffield Crown Court: Group of men seeking 'revenge' attacked teenage boys with machetes & zombie knife

A group of four balaclava-clad men who subjected two teenage boys to a 'revenge' attack using a plethora of weapons including a baseball bat, zombie knife and machete have been jailed for more than half a century. 

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The four defendants - brothers John and Robert Mahoney, along with Kian Carte and Mark Siddall - carried out the brutal assault on the two boys, then aged 15 and 16-years-old, in a disused bookmakers in the Askern area of Doncaster on April 11, 2023. 

They 'only stopped when they thought he was dead'

In an emotional statement to Sheffield Crown Court, the mother of one of the two boys said the attack on her son 'only stopped when they thought he was dead'. 

Detective Sergeant Kath Coulter said of the assault: "This was an utterly abhorrent attack on two young boys who were left with severe injuries that will leave scars for the rest of their lives.

"Armed with baseball bats and machetes, the Mahoney brothers, Carte and Siddall beat the two youngsters to a pulp, with one of the boys having to resort to playing dead to stop them from attacking him.

"He was a vulnerable youngster who was in fear of his life after being subjected to a vicious and unprovoked attack and I can't imagine the fear, terror and pain these two boys experienced at the hands of their attackers, who soon fled the scene."

Hearings held at the court on February 1 and 6, 2024 were told how the group came at both boys, chopping, slashing and stabbing at the teens. 

The attack left the 16-year-old boy in so much pain he thought he was going to die, and as he was bleeding heavily from the head, he asked one of the masked group to kill him, due to the extent of his injuries. 

After his attackers fled, the teenager was rushed to hospital and underwent eight hours of surgery after suffering significant injuries to his arms, face, back and head.

The other 15-year-old victim was slashed and stabbed across his back by a zombie knife before staggering to an address in Manor Road where he was able to seek refuge.

He sustained deep cuts to his hand and back and suffered a serious head injury.

'You are all equally culpable for the serious injuries'

The Recorder of Sheffield, Judge Jeremy Richardson KC, told the four defendants: "Each of you took a different role, this was a joint attack in which you all participated. You are all equally culpable for the serious injuries."

Judge Richardson continued: "It appears that each of you have taken the law into your own hands for what you perceive was wrongful or unlawful conduct by one or both of the two complainants. If either one of them had broken the law, it’s for the police to investigate, it’s for the courts to determine guilt or not."

Judge Richardson said the 'catalys' for the violence appears to have been centred around a stolen bicycle and a request for it to be returned. 

"This, in due course, led to an incident in which a car in which John Mahoney and his family were travelling was overturned by a large industrial digger."

Judge Richardson said the four defendants then set about 'planning' their 'retribution' which took the form of serious violence. 

The mothers of the two boys both described how they had both been forced to move their families out of the Askern area of Doncaster in the wake of the attack for fear of reprisals. 

Jerry cans with the words 'don't grass' found outside 'relevant homes'

Prosecutor, Richard Thyne KC, said 'jerry cans were found outside relevant homes' with the words 'don’t grass' written on them in the days following the attack.

There is no evidence to suggest any of the four defendants were 'directly responsible,' continued Mr Thyne. 

The mother of one of the boys said in her statement to the court that she was aware that her son had been 'recruited' to sell drugs, adding that she thought it was possibly for the defendant Carte, who was also brought before Judge Richardson to be sentenced for an offence of possession with intent to supply cocaine, which dates back to October 2022. 

Mr Thyne told the court: "Whatever the possible motive, the prosecution say it may probably be inferred that that [the boy] was seen to have crossed the defendants, and the attack on April 11 was a revenge attack."

The mothers of both boys said both they, and their families, have been left traumatised by the attack, and both boys are still in pain from their injuries. 

Siddall was also brought before the court to be sentenced for a second assault which was carried out in August 2022, after the complainant approached a van occupied by Siddall’s co-accused. 

Laura Marshall, prosecutor for the second assault, said the complainant was attacked from behind five days later, outside his home while his 11-year-old son was with him. 

Guilty pleas

John Mahoney, aged 38, of Laurel Terrace, Skellow, Doncaster; Robert Mahoney, aged 41, of Crossfield Lane, Skellow, Doncaster; Carte, aged 22, also of Laurel Terrace, Skellow, Doncaster and Siddall, aged 39, Acacia Road, Cantley, Doncaster all pleaded guilty to two counts of causing grievous bodily harm with intent at earlier hearings. 

Siddall also pleaded guilty to an additional charge of assault occasioning actual bodily harm, while Carte admitted a further charge of possession with intent to supply a Class A drug, namely cocaine. 

Summarising the mitigation advanced on the defendants’ behalf, Judge Richardson said he had noted that John Mahoney had been 'deeply aggrieved' by what occurred concerning the vehicle containing him and his family being overturned. He also referred to the progress John Mahoney is said to have been making while in custody, noting that he is making the 'best of his time' behind bars. 

Moving to Robert Mahoney’s mitigation, Judge Richardson said the fact he has never been to prison before was advanced on his behalf.

"It was said to me that you’ve lost absolutely everything," continued Judge Richardson. 

Judge Richardson said Carte’s barrister, Nick Rhodes KC, suggested his role in the assault had been 'supportive’'and that he had not inflicted any injuries himself. 

Judge Richardson said Carte was 'relatively young,' and his growing maturity had been noted. 

Siddall’s mitigation centred around a plea for the principle of totality to be considered when passing sentence for multiple offences. 

'I hope the sentences served on them can give some closure to the two victims of this awful assault'

Judge Richardson sentenced the four defendants to a total of 53 years, eight months behind bars and told them: "There’s no doubt that each one of you sought to take the law into your own hands. That has no place in a civilised society.

"Each one of you deserve a substantial commensurate sentence for the protection of the public and the punishment of each of you."

John and Robert Mahoney were both sentenced to 13 years’ imprisonment. Carte received a sentence of 14 years, comprised of 13 years for the two GBH offences and a further year for the drug dealing matter, while Siddall received a sentence of 13 years, eight months behind bars, with 13 years for the GBH offences, and eight years for the assault occasioning actual bodily harm charge. 

A fifth defendant was also jailed for six months for his role in the assault involving Siddall.

Speaking after the group were jailed, DS Coulter added: "The four perpetrators were quickly identified and the investigative team has worked hard to secure convictions.

"I am pleased they have also been put behind bars for a lengthy amount of time and I hope the sentences served on them can give some closure to the two victims of this awful assault as they try to rebuild their lives and fully recover from the mental and physical trauma inflicted on them."