Sarah Sands, who is a mother of five, used to visit the elderly man at his London flat and bring him his meals before she found out that he was facing charges of child abuse.
On 28th November, the 32-year-old downed two bottles of wine and a bottle of brandy.
She then armed herself with a knife and went to confront Micahel Pleasted, stabbing him eight times.
According to the BBC, CCTV footage showed that she was in his block of flats for 20 minutes.
When she left with a knife in her hand, she reportedly told a neighbour: “Pretend you never saw me.”
Sarah Sands then went to the Isle of Dogs, where she put the knife and clothes she had been wearing in a plastic bag.
She then went to her stepson’s house and confessed what she had done - and she was eventually persuaded to hand herself in to the police.
Sarah Sands, according to police reports, told officers: “I took care of it. I stabbed him.”
She went on to add that Mr Pleasted had been “asking for trouble”.
Ms. Sands later said in a statement that she denied intending to kill Mr Pleasted or cause him serious bodily harm, claiming she went to confront him and took a knife for protection as she was scared.
The trial at the Old Bailey continues.