The New Zealand Police directive is that officers are to accompany all persons they suspect are mentally distressed to the hospital emergency department for assessment by mental health professionals. How frontline police officers work and interact in the hospital emergency department when accompanying persons suspected of being in mental distress, is not clearly understood. There is a paucity of knowledge of what officers do and how they interpret their role in this setting. Using a social constructivist grounded theory approach to address this knowledge gap, a two-fold question was asked:

1. What do New Zealand Police officers do in the hospital emergency department when accompanying persons in mental distress?
2. How do New Zealand Police officers manage these situations? The theory of doing your best was developed from interviewing 23 frontline police officers at three police stations in the North Island of New Zealand. When developing the theory, the core elements of grounded theory of simultaneous data collection and analysis, constructing codes and categories from data, constant comparative analysis, memoing and theoretical sampling were employed. However, this constructivist approach also included reflexivity and acknowledged the interpretive co-construction of the findings. Doing your best emerged as the central process that police officers use when working in the community and hospital emergency department with those in mental distress. Doing your best involves officers navigating between meeting obligations and negotiating challenges they confront when keeping all safe. Several notable findings emerged from this study. These are that an officer’s initial interaction with the mentally distressed individual is an influencing factor, and impacts how officers work with the person later in the hospital emergency department. Officers with personal experience (family or friend) with mental illness engage with the mentally distressed person more effectively than officers who lack this experience, or who have become desensitised. Challenges for officers when working with those in mental distress emanate from their interactions with their interagency partners, not the mentally distressed individual. Officers want change to occur at an organisational level as to how they currently respond to a person suspected of being in mental distress, and how they work with their interagency partners. Key challenges that officers encountered were: doing their best to meet their obligations (personal, professional, societal), making the right call and negotiating and navigating challenges in the emergency department. This study has given a voice, understanding and new knowledge of how New Zealand Police officers work and interact with the mentally distressed in the community and within the hospital emergency department. It has identified the challenges encountered by officers in both settings, and provides potential recommendations for New Zealand Police and their interagency partners.