A mother blamed her 'jealous' toddler son for beating up his 11-month-old baby brother and causing his death.
Emma Wilson, 25, allegedly took pictures of her baby son Callum before deliberately hurting him and then taking more pictures of his injuries.
But denying a charge of murder, she claimed in court that Callum's 23-month-old brother inflicted the injuries because he was 'jealous' because he no longer had all of his mother's attention.
Callum was rushed to John Radcliffe Hospital in Oxford in March, 2011, with a detached retina which had caused him to lose his sight and he also had multiple fractures and bruises all over his tiny body. He died two days later.
Jurors at the Old Bailey were shown a series of photos Wilson took of Callum in the weeks leading up to his death in which bruises and scratches can clearly be seen on his face.
But Wilson, from Windsor, Berkshire, said she had never hurt her son and claimed: "It's the best thing in the world being a mum."
She claimed his injuries must have been caused by her other son who would 'throw things at Callum and push him over'.
"He was boisterous and would get generally jealous of Callum," she told the court.
She claims she tried to seek advice from her parents, GP and a health visitor on how to deal with the sibling rivalry.
"My other son would be rough with him. He liked to grab Callum's face and would leave him with scratches and bruises," she told the court.
A post mortem revealed the baby had also suffered fractures to nine ribs, to his right arm and left leg and were caused two weeks before he died.
Wilson denies murder. The trial continues.