Jenny Morrison, 50, was due to break the news to Anthony Joseph - who believed he was the Son of God - at a halfway hostel from which he had hoped to be released into the community. The "highly respected and compassionate" social worker turned up at the meeting alone because her car was in the garage and she needed a lift. Other workers had originally arranged to be there.
The attack was so frenzied that Mr Joseph, 27, broke the first knife and calmly walked into the kitchen to get another before continuing his assault, the court was told. Mr Joseph repeatedly stabbed the woman who had been trying to help him make a new life and her screams echoed through the hostel, the jury heard.
Mr Joseph had not picked up his medical prescription for five months and had told fellow residents at the social services hostel that he was selling his pills to "clubbers" while taking a cocktail of heroin, crack cocaine and ecstasy himself.
Three weeks before the attack, care staff were well aware that he had stopped taking his medication yet he remained free to come and go as he pleased, the court heard. Upon his arrest he told police: "Dad, God, made me stab her."
Mr Joseph's behaviour had changed within a short while of his transfer to the hostel in Balham, south London, after being discharged from Springfield Psychiatric Hospital, Tooting. He became abusive, snarling, played loud music, drank heavily and was dishevelled, the court heard. He spoke to other residents of "eating flesh" and being "tortured by dark spirits." Staff at the hospital, disturbed by his behaviour as well as his lack of medication, and annoyed that he was failing to pay his pounds 5 weekly rent, asked for him to be readmitted to Springfield.
The hostel's head social worker, Barney Travers, said he had been "powerless" by law to force Mr Joseph to take his medication and that the young man had never been violent despite his abusive actions. It fell to Ms Morrison, on 23 November last year, to convince Mr Joseph to return voluntarily with her to the psychiatric hospital.
David Waters QC, prosecuting, said Mr Joseph, who denies murder, had for many years suffered from paranoid delusions that he was being pursued by a fascist group. He said that Mr Joseph did not want to return to the hospital because he did not feel he was mentally ill and felt that if he returned to the psychiatric unit he would be tortured by the group.
The case continues.