There is a reason the murder and torture of one tiny boy from the northwest of England has captured the world's attention for more than 25 years.
Anyone who has heard of what happened to James Bulger after he was abducted by 10-year-olds Jon Venables and Robert Thompson from a Merseyside shopping centre 1993 cannot unhear the sickening details or imagine the hell the 2-year-old must have gone through.
The torture his two young killers inflicted was so graphic and bizarre, and the haunting CCTV images of the young boy being led to his death became so imprinted on the minds of the British public, led to Venables and Thompson becoming the most despised people in the country, news.com.au reports.
Now, quarter of a century after the fateful day young James was taken away, a new documentary has given a disturbing new insight into the minds of the notorious killers and put forward a new theory as to why they did it.
CONTROVERSIAL NEW THEORY
James Bulger: The New Revelations, which has just aired on UK television suggests Thompson and Venables may have been partly motivated by envy of a child who was loved.
It quotes the 18-year-old Thompson's parole statement to suggest he had been subjected to violence during his childhood, and had from the age of 8 spent most of his time on the streets with "friends whose main occupation was committing crime and causing trouble".
It also reports that Venables' siblings had special educational needs and the family's social worker had noted the 10-year-old's jealousy of the attention they got.
Amanda Knowles, who managed the secure children's home where Thompson served his sentence, told the programme makers: "I was very struck by the likeness between the youngest child in Robert's family and Jamie.
"Similar age, similar looking child, blue eyes, blonde hair, beautiful.
"I thought about it at the time, and I've reflected on it since, whether there was some connection between a child who had perhaps experienced rejection through the arrival of another child in the family."
However, the new insight has not been welcomed by James' mum, Denise Fergus.
She took to Twitter to lash out at its portrayal of the killers.
"I've needed to watch the disgusting @channel5_tv @caravan__media documentary, to know what I'm having to cope with," she wrote.
"I can actually say I'm upset, fuming with the 1 sided sympathy with the evil killers of my lovely son who was solely 2 yrs previous after they kidnapped & murdered him."
She was supported by hundreds of angry supporters who took aim at the new documentary.
"Honestly cannot believe that documentary on James Bulger," wrote angered Twitter commenter. "Why are they trying to defend them!! Yes they might have had a bad upbringing but at 10 years old I definitely knew it wasn't okay to kill. Fuming."
"Why does anybody feel that now is the time for their emotions and upbringings to be explained?" added another.
The documentary also suggests Thompson and Venables may have resorted to killing James out of panic and not knowing what to do with him once they had abducted him.
Knowles said: "I always had a sense that, having done something that they knew to be wrong, taking this little boy away from his mum, the fear and anxiety of being in trouble became a sense of panic and a need to hide what they'd done."
KILLER COULD "SMELL BABIES"
The documentary, revealed Venables — now 35 — was so haunted by his toddler victim he detected a "baby smell" on every item of clothing he wore to the 1993 murder trial.
He is reported to have said: "I can smell James like a baby smell."
The documentary also claims the killer would also ask his parents: "Do you think baby James is there in the courtroom?"
Thompson is said to have asked police whether the 2-year-old had been taken to hospital to "get him alive again".
Venables was so haunted by guilt he began to imagine a baby James growing inside him as if he could make things right again by giving birth and new life to his victim.
David James Smith, a journalist who covered the trial and wrote a book about the case, told the documentary makers: "Bearing in mind he [Thompson] was only 10, it makes you wonder what he really understood of what he'd done.
"I began increasingly to wonder what on earth they were doing there in the court, how could they play an effective part in the proceedings, and for whose benefit were they there?"
THOMPSON A "BETTER PERSON"
The documentary also revealed disturbing new statements which show Thompson, now 36, saying he was a "better person" due to his years in jail for the abduction and murder.
"I do feel aware I am now a better person and have had a better life and a better education than if I had not committed the murder," he can be heard saying in the incredible unearthed footage.
"At that time of my life, I was completely out of control and spending time with a group of friends whose main occupation was committing crime and causing trouble.
"I was out of control because my life on the streets was better for me than my life at home — there was nothing for me at home."
He appeared to understand how the comments, which were obtained by British media ahead of the broadcast, would be viewed.
"There is obviously an irony to this, but it is part of my remorseful feelings as well," Thompson said.
"I, personally, wish Mr and Mrs Bulger and their families to know that I am desperately sorry for what I did, and aware of the enormity of what I did."
Mr Bulger said the statements — and the messages they conveyed "terrifies me".
"The message here is horrific — kill a child and you will get a privileged and cosy life in return.
"They got a first-class education, counsellors and therapists while James's family was thrown to the wolves with our grief," he told The Mirror.
"It terrifies me that this sends out a message that you can commit a crime as heinous as killing James and get away with it."
WHAT HAPPENED TO JAMES?
Thompson and Venables took James to a railway line and tortured, beat and sexually assaulted him.
They poured modelling paint into his eyes, stoned him and clubbed him with bricks, before leaving him on the railway line to be hit by a train.
After killing him they left his body near the tracks where it was discovered two days later.
They were tried as adults and sentenced to eight years in a secure youth accommodation facility.
Thompson said he was "deeply ashamed" for the role he played, as he gave a new insight into what happened that day.
Neither boy gave evidence at trial and have never commented publicly about what happened.
According to his statement, he denied the pair sexually assaulted James.
In November 1993 the two boys were convicted of murder and ordered to be detained at Her Majesty's pleasure, the youth equivalent of an adult life sentence.
Afterwards, a crowd of 200 watched two police vans leave Preston Crown Court, to cries of "kill them" and "hang them".
WHAT HAPPENED TO THE KILLERS?
In June 2001, both the killers were released and given new secret identities.
However, in 2010 Venables was jailed for two years after admitting downloading and distributing indecent images of children.
It later emerged that Venables is back in jail after being caught with more vile child abuse images.
In February of this year, he admitted having a sick paedophile manual which instructed him on how to "have sex with little girls".
The killer, who also pleaded guilty to having more than 1000 indecent images of children, was jailed for 40 months.
Thompson has not reoffended since being released on parole when he turned 18.
His identity is protected by a worldwide injunction, so little can ever be reported about him.
However, it emerged in 2006 that he was in a stable gay relationship and had settled well into his local community in the northwest of England.
It is believed Thompson remains in a long-term relationship with a man who knows his real identity.