Rebecca Lewis accepted she had a duty to protect her son

Rebecca Lewis, 21, from Swansea, denies familial homicide by letting Andrew Lloyd kill 13-month-old Aaron Gilbert.

Her partner Lloyd, 23, admitted murdering Aaron, who died of brain damage and suffered 50 injuries.

Mr Justice Langstaff began his summing up of the case for the jury on Tuesday, and will conclude on Wednesday morning.

He told the jury Aaron was pronounced dead on the morning of 6 May 2005 after an 18-hour attempt to save his life.

The 13-month-old had 50 separate marks on his body, 48 of which were non-accidental.

The judge said it would never be known whether one, or more than one, injury had caused the brain damage which resulted in Aaron's death but there was no dispute that the fatal injury was inflicted by Lloyd.

Andrew Lloyd changed his plea after hearing medical evidence

He told the jury they must decide the prosecution had proven four things in order to find Miss Lewis guilty:

He summarised the evidence Miss Lewis had given, including how she had seen Lloyd flicking her baby's ears, throwing him on the settee and a mattress and picking him up by the ears.

The trial had previously heard Miss Lewis admit she left Lloyd mistreat Aaron because she feared for her own safety, but she did not think he would seriously hurt the baby.

She told the court Lloyd had threatened to kill her if she left him.

Mr Justice Langstaff said Miss Lewis had accepted she had a duty to protect Aaron, including protecting him from Lloyd.

Lloyd, who was not the baby's father, initially pleaded not guilty to murdering Aaron but changed his plea when he heard the evidence. He will be sentenced at a later date to life in prison.