24 June 2022
At 5.46am on Saturday 31 July 2021, a mother from Bridgend made a frantic phone call to police, informing them her five-year-old son was missing. We later learn his mother, Angharad Williamson, is one of three people held responsible for his death.
Following the sentencing of the three defendants on Thursday, 30 June, a new S4C documentary, Llofruddiaeth Logan Mwangi, shines a light on how the complex police investigation unfolded in a case where every second mattered in the hunt for evidence.
Access to CCTV, body-cam footage, witness statements and police interviews shows how police were able to piece together what happened before and after Logan's death and ultimately, bring the defendants to justice.
More follows - this page will be updated on 28 June 2022.
28 June 2022
At 5.46am on Saturday 31 July 2021, a mother from Bridgend made a frantic phone call to police, informing them her five-year-old son was missing.
Police operator recordings capture her chilling voice screaming: "Please, please help me, please. My son is missing. Please help me, this is my baby."
As the sad news of the little boy's fate emerged, his name - Logan Mwangi, has become familiar to us through news headlines.
We also know by now that the caller, his mother Angharad Williamson, is one of three people held responsible for his tragic death.
A new S4C documentary, Llofruddiaeth Logan Mwangi, shines a light on how the complex investigation unfolded in a case where every second mattered in the hunt for evidence.
"This is one of the worst cases I've worked on," said DS Ed Griffith, one of the detectives leading the investigation. "Ten out of ten on the scale to be honest. This will live with me forever".
Due to the suspicious circumstances, the Major Crime unit were quickly called in.
Disclosure Officer, Huw Griffiths, said: "Right from the start we thought this is unusual. Five-year-olds don't tend to get out of the house at three, four, five o'clock in the morning, wander out and go into the river."
"When you have three in custody, we look and compare what they say and look for provable lies.
"There were four in the house. Sadly one died. That left three behind.
"Now did one of them do it? Two of them? Or were they all responsible for the murder of Logan Mwangi?".
The programme reveals how police, led by DCI Mark O'Shea and DI Lianne Rees, used skill, determination and elements of luck to bring Angharad Williamson, her partner John Cole and a youth that cannot be named to justice.
It is a rare opportunity to follow a high-profile murder investigation from the moment police were involved and the crucial hours that followed.
We get exclusive access to the CCTV footage and witness statements that enabled South Wales Police to unravel the defendants lies and piece together the tragic sequence of events before and after Logans' death.
Body cam footage follows police officers from their first moments on the scene and officers give detailed accounts of the investigation as it unfolds.
We are given details of the detailed forensic work required to help piece together what could have happened to Logan in the last hours of his life.
The documentary shows the three defendants being arrested as well as crucial moments of Williamson and Cole's interviews.
We are shown the dramatic moment that Williamson changes her story after being presented with damning evidence.
We also follow the police on a poignant journey to see Logan's father, Ben Mwangi, to share the pathologist report outlining the horrific injuries that caused his son's untimely death.
Its findings note Logan had an 80% chance of survival, had he received medical help in time.
Mr Mwangi also reveals how Williamson had blocked his number in a bid to stop him from seeing his son.
"If I can stop this from happening to anyone else then that will be the best positive thing, apart from justice for Logan" says Mr Mwangi.
Llofruddiaeth Logan Mwangi
Thursday 30 June, 9.00 English subtitles available
On S4C Clic, BBC iPlayer and other platforms
A Multistory Cymru production for S4C