Police, Policing - the civil force of a state, responsible for the prevention and detection of crime and the maintenance of public order;
Social Work - work carried out by trained personnel with the aim of alleviating the conditions of those people in a community suffering from social deprivation;
Mental Health Professional is not defined in the dictionary but one would presume a trained person who cares for and treats people with mental illness. (If only they realised this).
Nonetheless, all three on a basic level have distinctly differing roles - but the latter two seem to think their work also lies within the realm of the Police.
Multi-agency working, as it is nicely dressed up in this modern age of fluffy catchphrases, shouldn't be about the Police picking up the slack left by the failings of other agencies, rather it should be about them doing their job so that we have a much smoother and more cohesive environment in which individual responsibilities are properly adopted.