A six-week-old baby was beaten to death by his mother's boyfriend, while she was on her first night out after his birth, a court has heard.
Alfie Sullock, from Fairwater in Cardiff, died in August last year. His mother's partner, Michael Pearce is on trial at Newport Crown Court accused of murder.
Prosecutor Michael Mather-Lees QC told jury members the baby boy was attacked with bottles of bubble bath, baby powder and a baseball boot.
Mr Mather-Lees said Ms Sullock met Pearce when she was nine-weeks pregnant and they began dating. He said Pearce was 'perfectly behaved' but started to show 'obsessive tendencies.'
Pearce offered to look after Alfie at his home in Nelson, Caerphilly, on 16th August last year while his mother Donna Sullock, 29, was out with friends. It was the first time he'd been left alone with the baby.
Mr Mather-Lees told the court Pearce sent Ms Sullock two photos of Alfie asleep and text her at 7.05pm to say the baby was fine and sleeping. Four minutes later, Pearce phoned 999 and when the ambulance arrived Alfie was "blue, cold and totally lifeless."
He was taken to the University Hospital of Wales, in Cardiff, where he was born just weeks before. Doctors found he had extensive brain damage and severe asphyxia and his life machine was switched off.
A post-mortem showed Alfie suffered blunt trauma injury and extensive bleeding to the brain. The court heard Pearce has not been able to give any explanation as to how the baby sustained his injuries.
He denies both murder and manslaughter. The trial continues.