A 52-year-old woman has gone on trial at the Central Criminal Court charged with the murder of pensioner Walter Plunkett almost two years ago.
Caroline Roche of Ballyedmond, Gorey Co Wexford pleaded not guilty by reason of insanity to the murder of her 84-year-old partner at Ballyedmond on 19 August 2012.
The couple had lived together for more than ten years.
The jury heard she had suffered from schizophrenia for many years and at the time of the incident she said she had missed a fortnightly injection she received for her condition.
In her garda interviews she said she and Mr Plunkett "were madly in love until the devil came along".
She said "the devil had been building for a while" and they had been fighting.
They had previously argued about cigarettes and the Lotto.
She told gardaí that at the time she attacked him she feared he was going to rape her but she later told gardaí he would not have done that.
Mr Plunkett died from asphyxiation and had multiple wounds to his head and body and fractured ribs.
The court was told that hours before the killing Ms Roche was seen sitting on the road outside her house in a trance-like state wearing only a T-shirt with an injury to her knee.
An ambulance was called but she assured ambulance staff she did not need medical attention.
Mr Plunkett was not at home at that time and was later seen in his car outside the house.
Some time later in the afternoon Ms Roche phoned gardaí to say she had murdered Mr Plunkett.
A recording of the 999 call was played to the jury during which Ms Roche said she had "bashed his brains in, smothered him, broke his fingers and did everything to him".
She later told gardaí she was glad she had killed him and that she had thought he was going to rape her.
When gardaí arrived to the house they found Mr Plunkett's body outside the house.
Ms Roche was found in the hallway dressed only in a T-shirt and naked from the waist down.
She told gardaí she had killed him, saying: "I'm glad I did it. It was me or him. It was self defence."
She said she had locked herself into his car after the attack as she feared he was going to get up and come after her.
She was taken to Wexford Garda station where a doctor deemed her unfit for interview and she was detained in a psychiatric overnight.
In hospital she re-enacted what she had done and said she was not sorry.
A doctor said she had suffered a relapse of psychotic schizophrenia but she was deemed fit to be interviewed the following day.
In her garda interviews she said she and Mr Plunkett had known each other 17 years and were madly in love "until the devil came along".
She said schizophrenia "had a lot to do with the religion" and she could never watch TV after being told about the devil in school.
She said she had been on medication since the age of 18 and had not received her regular injection at the time of the killing.
Senior Counsel for the prosecution Paul Burns told the jury members they may return a special verdict of not guilty by reason of insanity if after hearing the evidence of a consultant psychiatrist they were satisfied that at the time of the killing she was suffering from a mental disorder and ought not to be held responsible for her actions.
Medical evidence will be heard tomorrow when the case resumes.