A woman is accused of stabbing her boyfriend to death at their home and leaving his corpse to decompose in their bedroom for up to nine days, a court heard.
Joanna Cierpka, 51, tried to cut her throat with an eight-inch kitchen knife when police officers stormed her apartment in Newington Causeway, Elephant and Castle, on March 15.
Police found the partially decomposed body of 52-year-old Henrik Slotsaa lying in the bedroom.
‘It was clear he had been dead for some time, as his body showed signs of decomposition, and there was dried, pooled blood near to him,’ Danny Robinson, KC, prosecuting, said.
Cierpka, originally from Gdynia, Poland, was disarmed and told police: ‘I don’t want to be helped. You know what happened here? He told me I’m a useless sh-t. He told me I should kill myself’.
She had a deep cut to her elbow and was taken to hospital, where she allegedly told a member of staff: ‘I killed my partner.’
Cierpka denies murder, but she has admitted manslaughter.
Mr Robinson told jurors Mr Slotsaa, originally from Denmark, worked as a banker at Citibank’s London office in Canary Wharf while Cierpka had worked for British American Tobacco before she was made redundant.
He said: ‘There is no dispute that Miss Cierpka killed Mr Slotsaa by stabbing him with a kitchen knife. The issue in this case is whether she is guilty of murder, or whether she bears a lesser degree of responsibility for his death because of her mental state at the time she stabbed him, in which case she is guilty of the lesser offence of manslaughter.
‘She has already pleaded guilty to manslaughter, but the prosecution do not accept that her plea of guilty to manslaughter adequately reflects her responsibility for his death. We say she is guilty of the murder of Henrik Slotsaa.’
Jurors were told pathologists later found 14 separate ‘sharp force injuries’ on Mr Slotsaa, with ‘slash and stab wounds to the face, neck, arms, and legs’.
The prosecutor added: ‘There were also unusual wounds to the backs of both knees that may have represented an attempt at dismemberment.’
Police officers were carrying out a welfare check on Cierpka when they broke down her front door, the court heard.
Mr Robinson said: ‘It was only because of the email that Miss Cierpka sent to her family and friends saying that she was going to commit suicide that police went round to the flat on March 15.
‘The body-worn footage shows how untidy the flat was, with many empty bottles of wine on the coffee table in the lounge and on the kitchen counters.’
Jurors heard friends noted Cierpka had been ‘in a bad way’ since she was made redundant from her marketing job at British American Tobacco where she had been the ‘life and soul of the party’.
In the weeks leading to the killing, friends say Mr Slotsaa had been ‘flirting’ with a female work colleague and had told Cierpka on her birthday that ‘he had met someone else at work.’
Jurors heard Aimee O’Shaughnessy started work at Citibank last September. She disclosed that she was going through a divorce, and they swapped numbers, the court heard.
‘Throughout January 2026 Mr Slotsaa and Miss O’Shaughnessy met up for lunch on several occasions,’ said Mr Robinson.
‘Mr Slotsaa told Miss O’Shaughnessy that things weren’t great at home, and he told Miss O’Shaughnessy that he liked her. She said that her life was a mess and she didn’t want to complicate things by starting a relationship with him. According to her, he was fine with this.’
Mr Slotsaa continued to exchange messages with Miss O’Shaughnessy over the weekend of March 6 to 8, continuing until March 11.
The prosecutor added: ‘It is not known with certainty which of the messages from Mr Slotsaa’s phone were sent by him and which were sent by Miss Cierpka, although it is very likely that messages sent after Sunday 8 March were not sent by Mr. Slotsaa, as he was probably dead by then.’
In the week leading up to March 13, before police officers found his body, work colleagues became ‘increasingly concerned’ for Mr Slotsaa’s welfare because they couldn’t contact him.
Police eventually broke into the apartment and found Mr Slotsaa in his underwear, ‘kneeling on the floor, with his thighs parallel to the end of the bed.’
Mr Robinson told jurors: ‘After her arrest, Cierpka told a psychiatrist that in December 2025 Mr Slotsaa had told her he didn’t love her anymore, and that on her birthday he told her that he had met someone else at work.’
Cierpka admitted manslaughter but denied murder. The trial continues.
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