A father killed his newborn baby by shaking him so hard he inflicted force similar to a car accident or a fall from a multi-storey building, a murder trial has heard.
Abel-Jax Mailey was just seven weeks old when his father Oliver Mailey inflicted the fatal injuries on him.
The 26-year-old initially claimed he found his son limp and lifeless in his cot, but then admitted he had shaken the infant.
Mailey has pleaded guilty to manslaughter but denies murder.
Prosecutor Timothy Cray KC told Preston Crown Court that Mailey had been in charge of Abel-Jax at their home in Burnley, Lancashire, in November 2021 while his mother was at work.
Within an hour of her leaving, the baby had suffered serious injuries and needed to be taken to hospital by ambulance.
Mailey first claimed his son went limp while he was giving him a bottle. On a 999 call, he said he had no idea what happened but said "he's gone right limp, he's gone weird".
Abel died on the evening of 30 November after life support was withdrawn.
An examination found he suffered a catalogue of injuries, including catastrophic brain damage and severe bleeding and tearing injuries in his eyes.
The court heard that the damage to his brain meant he would have stopped breathing and his brain would have been deprived of oxygen.
Cray explained that doctors agreed the injuries were consistent with "forceful and deliberate shaking" on the morning in question and led to the baby's death.
He told the jury that evidence was also found of previous incidents to Abel’s brain which suggested he had been shaken before, as well as injuries to his ribs.
The prosecutor said the injuries could not have been caused accidentally and could only otherwise happen in a situation such as a "car accident or fall from a multi-storey building".
He told the jury: "This defendant does not dispute that he shook Abel on the Sunday morning, that the shaking caused Abel’s death, and that his acts were unlawful.
"The big factual issue that leaves for you is what he intended when he picked up Abel and shook him, in particular, did he intend to cause Abel really serious bodily harm? The defendant says that is not what he intended, and so he denies murder."
The court heard that Mailey had repeatedly challenged the baby's mother on whether he was his because he knew he had a low sperm count, and had moved out for a few months before the baby was born.
They eventually reconciled but problems remained, the court heard.
Cray said there was also little money in the house and both of Abel's parents were regular cannabis users, but there were no signs of neglect in the house and it appeared that the baby was a well-cared-for child.
He added that phone records showed Mailey was arranging to buy cannabis on the Sunday morning that Abel was killed.
The court heard that during a routine visit, a health visitor identified no cause for concern but specifically explained the dangers of shaking a baby.
Concerns had been noted by Abel's mother's godmother, who called at the house when Mailey was looking after the baby alone and noticed the infant screaming with particular distress and was concerned about what appeared to be a fresh bruise developing on his ear.
Once medical examinations were completed, Mailey was arrested in July 2022 but gave no comment in interview.
He denies murder. The trial continues.