The use of firearms by police in mental health-related events has not been previously researched in New Zealand. This study analysed reports of investigations carried out by the Independent Police Conduct Authority between 1995 and 2019. We extracted data relating to mental health state, demographics, setting, police response, outcome of shooting, and whether the individual was known to police, mental health services, and with a history of mental distress or drug use. Of the 258 reports analysed, 47 (18%) involved mental health-related events compared to 211 (82%) classified as non-mental health events. Nineteen (40.4%) of the 47 mental health events resulted in shootings, compared to 31 (14.8%) of the 211 non-mental health events. Of the 50 cases that involved shootings 38% (n = 19) were identified as mental health events compared to 62% (n = 31) non-mental health events. Over half of the mental health events (n = 11, 57.9%) resulted in fatalities, compared to 35.5% (n = 11) of the non-mental health events. Cases predominantly involved young males. We could not ascertain the ethnicity of individuals from the IPCA reports. Across all shooting events, a high proportion of individuals possessed a weapon, predominantly either a firearm or a knife, and just under half were known to police and had known substance use. Of the 19 mental health events, 47.4% (n = 9) of individuals were known to mental health services and in 89.5% (n = 17) of cases whānau (family) were aware of the individual's current (at the time of the event) mental health distress and/or history. These findings suggest opportunities to prevent the escalation of events to the point where they involve shootings. Lack of ethnicity data limits the accountability of the IPCA and is an impediment to informed discussion of police response to people of different ethnicities, and Māori in particular, in New Zealand.

新西兰以前没有研究过警察在心理健康相关事件中使用枪支的情况。本研究分析了独立警察行为监管局在 1995 年至 2019 年期间开展的调查报告。我们提取了与心理健康状况、人口统计、环境、警察反应、枪击结果以及此人是否为警察所知、心理健康有关的数据服务，并且有精神困扰或吸毒史。在分析的 258 份报告中，47 份（18%）涉及心理健康相关事件，而 211 份（82%）被归类为非心理健康事件。47 起精神健康事件中有 19 起 (40.4%) 导致枪击，而 211 起非精神健康事件中有 31 起 (14.8%) 导致枪击。在涉及枪击的 50 起案件中，38% ( n = 19) 被确定为心理健康事件，而 62% ( n  = 31) 是非心理健康事件。超过一半的心理健康事件 ( n  = 11, 57.9%) 导致死亡，而非心理健康事件的这一比例为 35.5% (n = 11)。案件主要涉及年轻男性。我们无法从 IPCA 报告中确定个人的种族。在所有枪击事件中，很大一部分人拥有武器，主要是枪支或刀，只有不到一半的人为警方所知，并且知道使用药物。在 19 起心理健康事件中，47.4% ( n  = 9) 的人为心理健康服务所知，89.5% ( n = 17) 例 whānau（家人）知道个人当前（事件发生时）的心理健康困扰和/或病史。这些发现表明有机会防止事件升级到涉及枪击的程度。缺乏种族数据限制了 IPCA 的问责制，并且阻碍了就新西兰警方对不同种族尤其是毛利人的反应进行知情讨论。