A Hertfordshire mother-of-two was stabbed to death by an intruder as her children slept and her husband listened helplessly on the phone, a court has heard. Nicola Cross, 37, was attacked by stranger Marcin Porczynski who broke into her Hemel Hempstead home on 14 September 2015.

Cross, whose husband Danny was working in Hull, had earlier called police when the Polish mechanic had banged on the door of her Dunlin Road home and stared through the window. Police searched and questioned Porczynski, who seemed "distant" and "confused," but didn't detain him. Porczynski returned to his home a few streets away then went back to Dunlin Road.

After smashing the patio door of a neighbour, who challenged him and called police, Porczynski smashed his way into the home of Mrs Cross as she was on the phone to her husband.

"She was on her phone to her husband again saying how worried she was when the defendant broke in. She said she heard a noise and told her husband to hold on while she went to investigate," Christopher Donnellan QC, prosecuting, told St Albans Crown Court.

"He heard her screaming: 'Get out of my house, what do you want?' He then heard further screaming: 'You don't need to do this.' Then her husband heard a male voice saying: 'I do, I do.' After a further very loud scream it went quiet."

In court Porczynski denied murder but admitted manslaughter on the grounds of diminished responsibility, which was accepted by the prosecution. He said he had heard voices telling him to "save" Cross's children or his family in Poland would be in danger. After attempting to take the children with him, who refused, he was attempting to leave the property when police arrived.

One of the children told police: "He has hurt my mummy badly." Upstairs they found Mrs Cross, who had been stabbed 10 times in the abdomen. The children were not physically harmed.

Porczynski, who according to The Guardian is currently detained at Rampton hospital, had no prior history of mental illness and neither he nor his family had been aware of the condition, though his housemate became concerned three weeks earlier. Porczynski will be sentenced on Monday 19 December.

In an impact statement read out in court as relatives sobbed, Cross's husband Danny said: "I was on the phone before, during and after. That phone call plays over and over in my head, along with Nik's screams and her pleading for her life. I will never forgive myself for not being there to protect her. I am totally and utterly heartbroken."