Logan’s body was discovered in the River Ogmore in Bridgend on 31 July 2021 – just 250 metres from his home.
A trial at Cardiff Crown Court heard he had suffered 56 external cuts and bruises, as well as “catastrophic” internal injuries.
He was wearing mismatched pyjamas and was said to have undergone a “brutal and sustained assault”.
Logan’s injuries were described as similar to victims of high-speed crashes or people who had fallen from a height.
Angharad Williamson, 31, was found guilty of murder – alongside her 40-year-old partner John Cole and a 14-year-old boy who can’t be named for legal reasons.
She was told she would spend at least 28 years behind bars, while Cole will serve a minimum of 29 years.
The teenager will be detained for at least 15 years.
Prosecutors said Logan had been “dehumanised” in the months and weeks leading up to his death. His stammer had worsened, he wet himself more frequently, and had started to self-harm.
Cole had told friends that he didn’t like the boy – and it was claimed that his attitude towards Logan changed after he became obsessed with the idea that Williamson had cheated with Logan’s father Ben Mwangi.
And a support worker had heard the 14-year-old singing: : “I love kids, I f****** love kids, I love to punch kids in the head, it’s orgasmic.”
A safeguarding referral was made after Logan suffered a broken arm in August 2020 – but a month before his death, the family were removed from the child protection register, meaning it was believed there was no longer a risk of significant harm.
Logan had also suffered a broken collarbone in the weeks before he died but never received medical treatment.
On 20 July 2021 – 11 days before his body was found – Logan tested positive for COVID and was shut in his bedroom, with a baby gate barring him from leaving.
Caroline Rees QC, prosecuting, said: “He had been kept like a prisoner in his small bedroom in the flat you saw, a room likened by Williamson as a dungeon.”
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