An elderly Irish man killed in north London last May suffered traumatic brain injuries associated with kicking and stamping, the Old Bailey has heard.
John Mackey, who was 87 years old, died two days after being attacked as he walked home from his local supermarket and takeaway.
Peter Augustine, aged 59, denies the charges of murder and robbery.
Mr Augustine appeared in court this morning but abruptly stood up and left the dock, indicating that he wanted to return to the cells.
He had been muttering to himself prior to leaving the court, something the prosecution described as "low level disruption".
Mr Augustine returned to the court before lunchtime.
Giving evidence this morning, Dr Matthew Cieka, a forensic pathologist, told the jury that Mr Mackey suffered multiple bruises and abrasions to his head, neck, back, arms and chest.
The pensioner also had two fractured ribs.
His head injuries are commonly associated with kicking, stamping and an accelerated unprotected fall.
The impact to Mr Mackey caused his brain to shift multiple times in his skull, the court heard.
There was evidence that Mr Mackey had Alzheimer's disease, however there was no underlying condition found that would have caused his death.
Dr Cieka concluded that Mr Mackey died from blunt force impacts to his head and chest.
He told the jury that many of his injuries were consistent with an assault as they could not be explained by a simple fall.
Mr Mackey died on 8 May, two days after he was attacked as he walked home from his local supermarket and takeaway.
He had purchased a Co-op branded cottage pie, cornflakes, a Daily Mirror newspaper and a takeaway meal of sausages and chips.
Mr Augustine was arrested at the nearby Beaconsfield Hotel on 8 May.
Upon his arrest, police found an empty cottage pie container, pack of cornflakes, takeaway container and a Daily Mirror newspaper dated 6 May in his hotel room. The food appeared to have been eaten.
