An 18-year-old woman was still alive when her boyfriend started to cut off her head with a knife, a jury has been told.
Aras Hussein, 21, killed Reema Ramzan by decapitating her at his flat in Sheffield before stabbing himself in the chest, the city's crown court heard today.
Prosecutor Graham Reeds QC told jurors about the wounds Miss Ramzan suffered at the hands of her Iraqi-born boyfriend on June 4, last year.
Mr Reeds said: "Bruising into tissue wounds suggest that Reema was still alive as the defendant started to remove her head.
"The process of decapitation would require considerable motion with corresponding considerable force which needed to be sustained until all the tissues had been cut through.
"Force would also be needed to restrain the victim who is likely to have been struggling.
"Severe force would have been needed to cut through the spinal vertebrae with a knife in order to remove the head."
Mr Reeds told the jury: " No-one can know what happened in that room immediately before the killing and what led to it."
He said Hussein was spotted naked outside his flat in Herries Road, Sheffield, with blood pouring out of his chest.
The prosecutor said the defendant told emergency workers who came to his aid: "I don't know why I did it."
He said Hussein told the paramedics: "She like me but I raped her. What I did was wrong. I need punishing for it."
And he told them: "Why are you helping me? I've murdered someone."
Hussein sat in the dock listening to Mr Reeds open the case for the prosecution, wearing a grey waistcoat, white shirt and striped tie and surrounded by guards.
He denies murder.
Mr Reeds told the jury Hussein is likely to claim he was suffering from diminished responsibility at the time of the attack due to schizophrenia.