Police responses to incidents involving people with a mental illness or suspected mental illness (PWMI) are a source of concern. On the one hand are high profile, although mercifully rare, interactions where police or PWMI are left dead or seriously injured. On the other, as the prevalence of PWMI experiencing crisis in the community increases, for a range of reasons, so does the resource commitment required by the police. Both concerns have led police to consider how they might better engage with specialist mental health care providers in tailoring their policing response. This article reports New South Wales Police Force’s attempts in this vein, and in particular, collaboration with stakeholders through the development of the Mental Health Intervention Team Program. First, this article sets out the importance of joined-up working in responding to mental health crises in the community. Then it considers the experience of the programme for partnership development and collaboration at the macro (legislative), meso (organizational) and micro (front line) levels. It concludes by identifying the lessons learnt and the implications for police and partners seeking to work together.