A sign at the home of the brothers who carried out the attacks
A relative of the boys who carried out the Edlington attacks has told how their mother would lace their food with cannabis to get them to go to sleep.
She recalled how the brothers grew up in a chaotic household watching horror movies from a young age.
The boys would often be up all night and had even set fire to their own wardrobes in their bedrooms, she said.
"You just knew one day they'd really hurt someone and that is exactly what they've done," she told the BBC.
The woman, who does not want to be identified, said: "They have always been naughty boys, but they could have been lovable kids given the right family."
She said the boys' mother would leave the children, who had been excluded from school, to their own devices.
"From the age of about six or seven they used to watch horror movies, Chucky films, the sort that grown-ups daren't watch.
"She [their mother] just sat in the house doing nothing really, she wasn't really bothered.
"The father used to do a lot more for the children than she did.
"He was a tough dad, maybe a little too tough and strict and they rebelled against him.
"If he smacked the boys for being naughty she would just tell them to tell him to F off, it doesn't matter.
Don Crabtree said the boys pulled up newly-planted trees in the park
"She used to put cannabis in the tea so they could have an early night and she could have a quiet night in.
"My friend said she had walked into the house one day and was totally disgusted because she had caught her putting cannabis on a chocolate cake."
A former police officer described the brothers as habitual troublemakers who were "a cancer" in the local community.
Don Crabtree said they were involved in incidents of vandalism and violence against animals.
He first came across the boys when he organised a tree planting scheme at Sandall Park in Doncaster in 2006.
"We invited this particular family who were in the park to help us plant," he said.
"They helped us for a day, there was a lot of work put in by the volunteers there, but within 20 minutes of leaving the site the entire area was trashed.
"Five hundred pounds worth of plants got pulled up and thrown in the lake. One particular member of that family was responsible.
"That person was identified to me by someone who saw them trashing the plants.
"On one occasion we had it reported to us that at least one member of that family was seen to pick up ducklings in the park and kill them by throwing them against trees.
"That is about as sad as it gets."