Social workers called for employers to follow hospitals and police forces and introduce risk assessment measures to reduce violence and stress to staff, just hours after Anthony Joseph was convicted of manslaughter on the grounds of diminished responsibility for murdering a social worker.

The Old Bailey heard that Joseph, who was diagnosed with paranoid schizophrenia, stabbed Jenny Morrison more than a 100 times last November after he was told he had to return to a psychiatric hospital. He was sentenced to indefinite detention at Broadmoor special hospital.

Graham Fanti, assistant director (England) of the British Association of Social Workers, said the trial highlighted the need to ensure the safety of social workers. "Resources should be released by social work employers to ensure that social workers and their managers are trained in risk assessment and that the necessary support is available to staff who have suffered as a consequence of trying to do a difficult job."

Joseph had delusions that he was the son of God and believed he would be tortured by members of the far right group Combat 18 if he was returned to Springfield Hospital in Tooting, south London.

In June 1998 Joseph had been transferred from hospital to a Balham halfway hostel in preparation for his release into the community. But by October his condition had deteriorated. The court heard Morrison came to be alone with Joseph after she arrived at the hostel ahead of colleagues.

Wandsworth social services department, the Merton, Sutton and Wandsworth Health Authority and the South West London and St George's Mental Health NHS Trust are reviewing safety standards.

An independent inquiry team will investigate the quality, scope and appropriateness of the care and treatment that Joseph received from social and health services, as well as the assessments which were made of the potential risk he posed to himself and others.

But Margaret Pedler, head of policy development at Mind, said compulsory treatment for people with mental health problems is not the solution despite this case. "We need vast improvements to risk assessment procedures and practices, but not compulsory medical treatments that will not work," she said.

n Community Care's campaign for safety in social work starts next week.