A woman has been accused of stabbing her City banker boyfriend to death at their home in Elephant and Castle, south London. Joanna Cierpka, 51, allegedly killed Henrik Slotsaa, 53, after he disclosed he had formed a relationship with a colleague, the Old Bailey court heard. The victim's body was reportedly found in their apartment days after the incident.

According to prosecuting barrister Danny Robinson KC, Cierpka stabbed Slotsaa 14 times and left his body in their shared flat for up to nine days. After the killing, she used his phone to send messages to his colleagues and acquaintances, including the woman with whom he was said to have been interacting closely, creating the impression that he was still alive. Police entered the flat on March 15 after receiving an email from Cierpka indicating she planned to end her own life. They found her attempting to cut her throat with a kitchen knife, amid a scene described as chaotic and marked by numerous empty wine bottles.

Slotsaa, a Danish citizen, was a vice-president at Citibank’s European headquarters in Canary Wharf, east London. Cierpka, originally from Poland, had worked in marketing research for British American Tobacco before being made redundant. The couple had been in a relationship since 2011, with friends noting that Cierpka had been severely affected by the loss of her job. A friend described her as once the "life and soul of the party," but said redundancy had damaged her self-confidence.

The court heard that the relationship between Cierpka and Slotsaa had deteriorated in the months before the killing, highlighted by Slotsaa’s admission to Cierpka on her birthday that he had met someone else at work. Witnesses also noted that he had been "flirting" with a female colleague, which appeared to have catalyzed tensions between the couple. Cierpka told police, “He told me I’m a useless shit. He told me I should kill myself.” Prosecutors stated there were signs Cierpka had attempted to dismember Slotsaa’s body; a post-mortem revealed multiple stab and slash wounds, including injuries to his face, neck, arms, legs, and backs of both knees.

Cierpka has pleaded guilty to manslaughter on the grounds of diminished responsibility but denies murder. The defence presented evidence from psychiatrist Penelope Brown, who diagnosed Cierpka with a depressive episode that impaired her judgment and self-control at the time of the killing. Brown argued that this condition justified a partial defence of diminished responsibility. On the other hand, psychiatrist Shamir Patel, instructed by the prosecution, acknowledged her depression but contested that this impaired her legal responsibility for the stabbing.

The trial remains ongoing as the court continues to examine the circumstances leading to Slotsaa’s death and Cierpka’s mental state during the incident.