Exclusive:Woman feared murder by “evil” boyfriend holding “big knife” who allegedly killed her sister

A sister told a court she feared would be murdered by an “evil” boyfriend holding a “big knife” who had allegedly just killed her younger sibling.

Arleta Derkacz told jurors at Portsmouth Crown Court she pushed past alleged killer Stephen Sexton, 38, after thinking she heard her sister Joanna Derkacz, 37, upstairs in the couple’s Nevinson Way home in Waterlooville on December 28, 2023.

But Arleta, who had gone to the house after being concerned about her sister’s welfare, found her sister lifeless in an upstairs bedroom.

Arleta told the court Sexton had initially denied Joanna was at the house before trying to stop the worried sister from going upstairs and had an “evil look on his face”.

Arleta told jurors: “I said, ‘I’m going upstairs.’ He said, ‘no you won’t.’ I pushed him with my left hand, 100 per cent.”

Defence barrister Jodie Mittel KC said the defendant had not tried to stop her which Arleta rejected and continued: “When I heard my sister’s voice I ran upstairs.” She then added: “When I heard her voice I thought he had beaten her up. When I went upstairs she was dead.”

After finding her dead sister, Arleta made her way back downstairs where Sexton was lurking with a knife. “After the whole shock of seeing my sister I couldn’t feel my legs. I asked him what he had done. He was holding a knife…he was ready for me to attack him but I didn’t because I froze and he put the knife to his wrist,” she said.

A sobbing Arleta then told the court she feared Sexton was going to kill her: “If I had not frozen and had physically attacked him I don’t know if I would be sitting here today.”

Ms Mittel conceded it was a “pretty big knife” but insisted Sexton was only “pointing it at his own wrist”.

Arleta escaped from the house after “grabbing the door handle” before her partner, who she had travelled to the house with, pulled her away.

The sister also backed up her claim in police interview that Joanna told her she had been strangled by Sexton on a previous occasion. “(Joanna) said, ‘he tried to strangle me,’” Arleta told the court.

The court previously heard post-mortem examinations found three broken bones in Derkacz's neck and DNA evidence that she had been sexually assaulted.

But following the first post mortem after Joanna’s death, Arleta said she was told by police: “Nothing has been found, so no cause of death.”

(Proceeding)