A teenage gamer who killed a 14-year-old sent pictures of the murdered boy to his friends, the victim's mother has said.
Computer engineer Lewis Daynes (19) admitted carrying out the murder after dramatically changing his plea on the day he was set to stand trial at Chelmsford Crown Court last week. He is due to be sentenced in the new year.
Barrister Richard Whittam QC told the court it was the prosecution's case that the murder "involved a sexual and sadistic motivation".
Speaking on BBC Radio 4, Breck Bednar's mother Lorin LaFave said she had tried to alert police to her suspicions he was being groomed.
Outlining how she first heard the news of her son's death, she said Breck's triplet siblings, who were 12, were contacted by those who had been forwarded photos of his body.
Daynes also posted images of his victim's body online.
She said: "Daynes sent photos of Breck in that state to some other boys and then they spread the message round. Those poor boys have to deal with that.
"That's how the triplets learnt - they received a text from other children at school who had siblings and that's how they were told."
Ms LaFave said she was speaking out to encourage other parents to be on their guard against child grooming online and because she felt great protection was needed from the UK government and law enforcement agencies.
"There's a perception that it only happens to people who don't have parents looking after them, but these predators are very good at controlling children and even trying to control me," she said.
The Breck Bednar Memorial Foundation has been set up to help raise money and awareness to help protect children.
It is understood Daynes and his victim met after playing online video games together.
After his death, family members said Breck, from Caterham, Surrey, left home after arranging to meet a friend online.
He was found more than 30 miles away in Grays with a fatal stab wound to the neck on February 17.
Breck was "extremely gifted in computing, electronics, and engineering", his family said.