What a pathetic posting 'margaretthatcherschild' - I find it to be offensive, totally unprofessional and almost (if not actually) indicating that social workers can be the authors of their own misfortune. Your posting would bring little comfort to the family of Philip Ellison.
I really think that you ought to think a little more before submitting such unwise comments.
Reality is that in working with the mentallty ill there are potentially additional risks to workers arising from the irrational and impusive actions sometimes displayed and that social workers (and others) will always be attacked and even killed.
Risk Assessments, accompanied visits, even wearing protective clothing can all help but none are any guarantee of safety. It is ill-advised to say what you COULD have done - those of us with a depth of experience know exactly what can happen but that does not stop us working with mentally ill clients (or, non-mentally ill ones who may feel that they / their children are at risk).