Teenager, 14, who murdered Logan Mwangi, 5, named as Craig Mulligan

The boy suffered 56 ‘catastrophic’ external injuries similar to those found in victims of a high-speed crash

A 14-year-old involved in the murder of five-year-old Logan Mwangi was named for the first time on Thursday as he was detained for life.

Craig Mulligan has been described as a “monster” who had made repeated threats to kill his stepbrother and gleefully chanted about his love of harming young children.

He was just 13 when he took part in the fatal assault, which he carried out with his stepfather John Cole, 40, before disposing of the youngster’s body in the River Ogmore, Bridgend, south Wales.

Cole was told by a judge at Cardiff Crown Court that he will spend at least 29 years behind bars. Logan’s biological mother Angharad Williamson, 31, who was also convicted, was told she will serve a minimum of 28 years’ custody .

Mulligan had moved into the house in Lower Llansantffraid, Sarn, only five days before the killing – a fact prosecutors said was “no coincidence”.

The stepson of Cole, who had brought him up from nine months old, Mulligan was said to have “idolised” him and seen him as a “God-like” figure.

Cole had been in a relationship with Mulligan’s mother, later becoming her carer.

The three moved to Wales for a “new start” after repeated attempts by Mulligan’s mother to take her own life.

They later split, but remained living in the same house with Mulligan, including while Cole began dating Angharad Williamson, who shortly afterwards became pregnant.

Caroline Rees QC, prosecuting, said by this time Mulligan was already “a complex, troubled and violent boy”.

He was placed with foster families, one of which described how he made their lives a “living hell” for the several weeks he lived with them, and they became “terrified” of him.

They said he made repeated threats to kill them, injured their daughter and the foster mother and their dog.

Concerns were further raised after he asked two young girls if they wanted to play a “murder game” and said they would have to get inside black bin bags.

Although he spoke fondly of his stepfather, stepmother and youngest sibling, the family said they noticed he would only refer to Logan as “the five-year-old”, and spoke of wanting to “kill the five-year-old”.

They said he had a “desire for violence”, and called him a “monster” in submissions to the court.

Cole and Williamson petitioned the family courts to have custody of Mulligan and on 26 July last year they won and he came to live with them.

It is said Mulligan loved the youngest of his stepsiblings but was jealous of and disliked Logan.

Mulligan was large for his age and had an interest in mixed martial arts, specifically Muay Thai, as well as video games, his username being “King hulk”.

Just before 3am on 31 July Mulligan was captured on CCTV cameras following Cole out of the flat and down to the river where they dumped Logan's body.

He also joined in carrying out a visible, fake search for Logan as part of the family’s cover-up.

Mulligan was arrested at around 6.30pm on 1 August along with Williamson inside Cole’s property.

During interviews he maintained he did not know what had happened to Logan but later admitted he had awoken to hear Williamson saying “Logan is dead”.

After being told by detectives about Williamson’s allegations that he and Cole had attacked Logan, Mulligan said: “You can tell my mum to f*** off for me. She’s blaming me and my dad for everything.”

After Logan was killed and Mulligan was once again in the care of the local authority, a care worker heard him repeatedly singing: “I love kids. I f***ing love kids. I love to punch kids in the head. It’s orgasmic.”

He told another: “I did some bad stuff but I’m not allowed to talk about it.”

During the trial an anonymity order was placed on Mulligan preventing the reporting of any detail that might identify him.

His counsel said Mulligan had been diagnosed with multiple neurodevelopmental disorders.

The River Ogmore in Sarn, Bridgend, Wales, in the vicinity where the body of five-year-old Logan Mwangi was discovered (PA)

Following his conviction and imprisonment for murder and perverting the course of justice, the press successfully applied to have the restriction removed on grounds of public interest and open justice.

Logan suffered 56 “catastrophic” external injuries similar to those found in victims of a high-speed crash or a fall from a height, the court was told.

During Thursday’s sentencing, Ms Justice Jefford said: “Inflicting these injuries on a small, defenceless five-year-old is nothing short of horrific.”

Both Williamson and Mulligan were found guilty of a further charge of perverting the course of justice – an offence Cole had admitted before trial.

Angharad Williamson, 31, and John Cole, 40, have been sentenced at Cardiff Crown Court (South Wales Police)

The youngster, described as a “smiling, cheerful little boy”, was found by police in the river on the morning of 31 July, partially submerged, and dressed in dinosaur pyjama bottoms and a Spider-Man top.

According to experts, Logan’s injuries could only have been the result of a “brutal and sustained assault” in the hours, or days, prior to his death.

They also said the injuries were “consistent with child abuse”.

Prosecutors told the court that Logan had been “dehumanised” by his family in the months and weeks leading up to his death.

The five-year-old’s stammer allegedly worsened, becoming particularly bad around Cole. He also wet himself more frequently and began self-harming.

Prosecutors said Logan, 5, was kept “like a prisoner” in his bedroom, a room likened by his mother to a “dungeon” (PA)

Friends of the couple said Cole told them he did not like Logan, and others said his attitude changed after becoming obsessed with the idea that Williamson had cheated with Logan’s father Ben Mwangi.

After Williamson gave birth, Cole was reluctant to let Logan see the baby and later claimed the boy had tried to smother the infant.

Medics made a safeguarding referral to the police after Logan suffered a broken arm in August 2020.

Councillor Huw David, leader of Bridgend County Borough Council, said: “The death of five-year-old Logan Mwangi has been a deeply sad and tragic affair which has affected all who live within Bridgend County Borough.

A memorial garden at Tondu Primary School in Bridgend for Logan Mwangi (PA)

“We are also united in our condemnation of the terrible actions of those who ended Logan’s short life in such a cruel and brutal way, and the great lengths they went to in trying to hide the evidence of what they did from the authorities.

“Throughout the trial of his murderers, Logan was consistently described as being a loving, kind and caring little boy, one who was polite and popular among his friends and fellow pupils.

“Listening to the tributes from Logan’s dad and his school, he was clearly a boy who brought joy and laughter to the lives of those he met, and it is hard to find adequate words for expressing just how devastating it is that such an awful murder could have happened in our county borough.”

Council chief executive Mark Shephard added: “Now that the trial has concluded, Cwm Taf Morgannwg Regional Safeguarding Board is leading on the commissioning of a child practice review to enable relevant agencies to fully assess and consider their roles, and to determine whether any improvements can be made to further strengthen the overall standard of local services.

“We are awaiting the review’s findings, and together with our partners we will implement any recommendations that it may contain to ensure that we can provide the best, most effective services possible for the local community.”

Additional reporting from Press Association