A TOP criminologist has revealed how Logan Mwangi’s “pure evil” teen killer Craig Mulligan gave himself away.
In reality, the teen monster had helped murder Logan along with Williamson, 31, and his stepdad John Cole, 40.
He was then captured on haunting CCTV carrying the dead youngster in a Nike holdall with Cole to a nearby river as the trio hatched a grisly scheme to cover up the killing.
Mulligan, Williamson and Cole were yesterday jailed for life with a minimum of 15 years for murder following Logan’s brutal killing.
Now, leading criminologist Dr Graham Hill claims Mulligan gives away seven suggestions of his guilt in newly released footage of his police interviews.
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The clip shows Mulligan claiming he and Cole had grabbed rubbish from the back garden and “chucked it in the river”.
Mulligan told officers he couldn’t remember what was in the black bags and claimed they returned to the river later to check they had “gone down”.
He added: “We were trying to be as quiet as we could as we didn’t want to wake Logan or Angharad.
“I don’t know whether Logan was still there at that point…I didn’t check”.
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But Mulligan snaps when it emerges Williamson has pinned her son’s killing on him and Cole.
Asked if there is anything he would like to add, the teen fumes: “Yeah. Can you tell my mum to f**k off for me.
“She’s blaming me and my dad for everything when we haven’t done anything. Now I’m sick of this – she’s just saying whatever she wants to get out of the f***ing cells.”
Dr Hill claims Mulligan’s lack of fear when being confronted by police is a key clue.
The criminologist said: “When I look at his non-verbal communication I don’t see anyone that’s intimidated by the process.
“He’s only 13 when he’s being interviewed. You would expect young children to be nervous about that process.
“Police have to be careful about how they interview adolescents. Normally they are quite timid and reserved in the way they present.
“He seems quite confident. He’s trying to front it out.
“What you see in that video is a snapshot of what he’s like but it’s 10 per cent of what his normal personality would be.”
Another clue is in his verbal aggression – namely him swearing at cops.
Because he can’t express his anger at Williamson physically, he does so verbally by swearing.
His speech also hides another clue. Mulligan’s swearing and Cole acting as a poor role model implies he likely had a limited education.
This means he may not have had positive role models to teach him key life skills – including empathy.
His lack of empathy – best seen in his blatant lies and lack of accountability – is another clue.
The “pure evil” teen, now 14, is the son of John Cole’s ex-partner Rebecca Trudgill, who was in a relationship with the monster for over ten years.
The relationship ended in 2019 when Cole met Williamson and the teen was taken into care after his mum faked a cancer diagnosis.
As he had criminal convictions, Cole, who Mulligan saw as a “God-like” figure, was banned from unsupervised contact with children.
But in May 2020, he applied to have parental rights of Mulligan – with the request granted just five days before Logan was killed.
Dr Hill added: “He’s started to idolise his step father who is clearly is a poor role model.
“So you end up with a man whose got a really warped or distorted moral compass.
“In his world what he does and what he says is ok because no one has ever given him any corrective parenting.
“So it seems to me that he is being allowed to do what he wants when he wants.
“And anyone who challenges him, he confronts with aggression and then they’ve backed down.
“So what that has taught him is if he’s verbally and physically aggressive he gets what he wants.”
Another sign of potential guilt is poor hygiene – signalling low self esteem.
“He looks overweight, he looks like he doesn’t look after himself very well.
“So you end up with low self esteem.
“If you look at this young man’s behaviour, there are so many red flags.
“There is the classic of physically and verbally aggressive, constant behavioural problems – being difficult to control.
“The classic cruelty to animals and other children. That is what we’d expect to see in a child like that – overt sadism.
“Poor hygiene is another one – these are all chronic behaviours that are classic signs of a child likely to go onto commit a serious offence.
“Low self esteem, a lack of empathy, physically and verbally aggressive, behavioural problems, difficulty regulating their behaviour, temper problems, cruelty to animals, cruelty to other children, poor hygiene.
“All of those are what’s known as chronic behavioural symptoms.”
If you look at this young man’s behaviour, there are so many red flags.
Logan was pulled from Ogmore River close to his home in Bridgend, South Wales, in mis-matched pyjamas in July last year.
He had suffered 56 external injuries to his head, face, torso arms and legs from “blunt force trauma”.
The horrific catalogue of injuries included a fractured shoulder, extensive bleeding to the scalp and back of his head and a significant trauma to the brain.
Logan had been so battered even his tongue was bruised but tragically he was still alive for several agonising hours after his liver and bowel were torn.
Had his evil killers called for help, the boy would have had an 80 per cent chance of survival.
Sentencing, Judge Mrs Justice Nerys Jefford described the attack on Logan as “ferocious”, adding: “You have all been convicted of murder and you are all responsible for Logan’s death and all the anguish that followed from that.”