Joanna Cierpka, 51, an unemployed business executive, told the Old Bailey that her partner, Henrik Slotsaa, a Citibank worker, had told her he no longer loved her and had met someone else on her birthday in January. The court heard that Cierpka was arrested after police found the 52-year-old's body at their home in Newington Causeway, Elephant and Castle, south London, on March 15 2026.
Giving evidence on Wednesday, Cierpka said she felt "sad" after seeing text chat between Mr Slotsaa and the other woman on his phone but did not feel able to confront him about it. The defendant described how her relationship with Mr Slotsaa and her mental health had deteriorated leading up to his death.
Defendant's account of taunts and threats
On February 19, Cierpka searched the internet for the phrases "I don't want to live anymore" and "how to end it", the court was told. Jacqueline Carey KC, defending, asked: "Did Henrik know how you were feeling at this time?" The defendant replied: "Yes. He didn't understand depression but I told him several times I don't want to live.
"He was saying that I'm only talking about it, not doing anything. Once also he told me that I make sure if I do it the flat (they jointly owned) fully goes to him. He was also really annoyed I scratched my eczema. He said: 'Kill yourself already, you freak.'"
Cierpka told jurors that days before Mr Slotsaa died she had looked up his female co-worker online because she was "just curious about the person I was supposed to be replaced with". Asked why she also searched for "artery and neck", the defendant said she wanted to kill herself.
Events leading up to the stabbing
Cierpka told jurors she did not know whether Mr Slotsaa had been alive or dead when she searched the internet for "the highest penalty in the UK" early on March 9. The defendant said she remembered going into the kitchen for a knife to kill herself and the next thing she was sitting in the living room with the blade on the coffee table.
She told jurors she did not remember cutting Mr Slotsaa's neck in the bedroom or how he sustained injuries to the back of his knees said to be consistent with an attempt at dismemberment. She told jurors she felt "mortified" as "it was me that was supposed to be dead". Explaining why she did not call police, she said: "I wanted to be dead before anyone found out."
In the week before Mr Slotsaa's body was found in the bedroom, Cierpka said she did not even change her clothes. Poland-born Cierpka studied marketing and management at university and completed a masters in financial services before joining British American Tobacco as a management trainee.
Background and relationship history
She had met Mr Slotsaa through an online dating site and moved in with him in London, eventually sharing a mortgage on their London flat. The defendant described how they used to enjoy an active social life with regular meals out and theatre trips. She found the coronavirus lockdown "extremely hard" and like a dystopian "Orwell book", the court heard.
At the end of 2020, Cierpka said she was made redundant and had struggled to look for a new job while depressed. The defendant told jurors how she had helped run a seasonal cafe in Greece and in 2024 worked briefly as a barista at Starbucks but failed to secure permanent employment.
Cierpka said her relationship with Mr Slotsaa deteriorated along with her mental health. She told jurors: "I felt really guilty that I cannot pull myself together and there was expectation to do something with my life. It was like daily battle with myself. I was spending most of my life on the sofa sometimes doing some stupid games on the phone sometimes just watching the ceiling. I stopped cooking so Henrik started buying the food ready to cook."
In 2025, her friend took her away to Greece where she engaged in a five-week fling with Dennis Leftakis, who ran a Taverna. Cierpka told jurors she was feeling "low" and it "just happened", even though she still loved Mr Slotsaa. On how she felt when she met Mr Slotsaa at the airport after spending the night with her lover, Cierpka said: "I started to feel better. You have this high and also when Henrik arrived he hugged me on the shoulder more like a mate. I wanted this feeling of being wanted to last."
She went on: "I was feeling very guilty on the one hand but it was also complicated because … it kind of felt we were growing apart and he chose to spend time in London." Ms Carey asked: "Did you tell Henrik what happened between you and Dennis?" Cierpka replied: "No. I loved Henrik. I didn't want to break this relationship. I felt guilty about what happened but I didn't believe telling him (sic)."
She has pleaded not guilty to murder, but she says she is guilty of manslaughter by reason of her diminished responsibility. The Old Bailey trial continues.
