ogan Mwangi’s mum, his stepdad and a teenage boy have been found guilty of his murder.
The “smiling, cheerful” five-year-old was found dumped in the River Ogmore in Pandy Park, Bridgend on July 31 in 2021.
Police officers found him partially submerged wearing a pair of dinosaur pyjama bottoms and a Spider-Man top just 250 metres from his home.
Ms Williamson and the 14-year-old defendant were also found guilty of perverting the course of justice.
She could be heard screaming “no, no, no” from the dock as the jury delivered their verdict.
Judge Mrs Justice Jefford told her to remain silent “out of respect for your son” and the teenage defendant.
The court heard that the youngster had suffered 56 external cuts and bruises as well as “catastrophic” internal injuries.
Experts said the injuries could have only been caused by a “brutal and sustained assault” inflicted on Logan in the hours, or days, prior his death. They also said the injuries were “consistent with child abuse”.
Prosecutors said Logan had been “dehumanised” by his family in the weeks leading up to his death. The child had begun to wet himself more frequently and began self-harming, jurors were told.
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 Williamson had cheated with Logan’s father Benjamin Mwangi.
Medics made a safeguarding referral to the police after Logan suffered a broken arm in August 2020, with Williamson saying he had fallen down the stairs.
She took him to hospital the day after the incident and said she thought he had only dislocated his shoulder and had tried to put it back.
Later she told a friend the youth had confessed to pushing Logan down the stairs but it was not until January last year she told the police.
By March, due to concerns over Cole, Logan and his younger sibling had been assigned their own social worker, Gaynor Rush.
In June, a month before Logan died, the family were removed from the child protection register – meaning it was believed there was no longer a risk of significant harm.
A foster family the youth stayed with claimed to have heard him say he wanted to kill Logan while a support worker also heard the youth, singing: “I love kids, I f****** love kids, I love to punch kids in the head, it’s orgasmic.”
On July 20 Logan tested positive for Covid and he was shut in his bedroom “like a prisoner” with a baby gate barring him from leaving, prosecutors said.
Williamson claimed that two days before Logan’s body was found an argument about a spilt drink escalated and ended with Cole and the youth attacking him.
She accused Cole of punching Logan twice in the stomach and ordering the youth to “sweep” Logan if he stuttered or flinched.
Moments later the youth carried out the martial arts-style manoeuvre, kicking his legs out from under him while using his hand to slam his head to the ground.
Williamson said she screamed for them to stop but said Cole replied: “The only way this boy understands is pain.”
Two days later, she phoned the police at 5.45am reporting Logan missing – claiming to have awoken to find him gone and accusing a woman of taking him.
Police arrived at the flat to find Williamson hysterical, while Cole and the youth could be seen walking around the area calling for him.
Prosecutors said this was part of an “elaborate” cover-up concocted by the defendants and all three were accused of perverting the course of justice, of which Williamson and youth were convicted.
Cole, who was captured on CCTV carrying Logan’s body to the river from the flat, while being followed by the youth, admitted the charge.
He claimed he woke to the sound of Williamson screaming Logan was dead and he panicked.
CCTV shows a bedroom light being switched on and off while Cole and the youth were out – the prosecution used this evidence to show Williamson was awake and aware Logan was dead.
Cole said after dumping the boy’s body, Williamson sent him out again to hide his ripped pyjama top.
The judge adjourned the case for sentencing at a date to be fixed.