Police officers are frequently exposed to critical and potentially traumatic incidents in their work. Exposure to critical incidents (CI) in policing is associated with an increased risk of developing mental health problems, in particular post-traumatic stress disorder. However, the definitions and understandings of police-specific CI vary extensively. The present qualitative study aimed to enhance our understanding of the core characteristics of work-related CI that are perceived as most burdensome among Danish police officers. Using content analysis, this study coded 2960 descriptions of work-related incidents that still cause emotional reactions among 1659 Danish police officers. The content analysis resulted in the development of three main categories of CI (danger or threat, accidents, and deaths and distressing crimes) which could be conceptualized in a diversity of 28 CI categories. Hereof, the main part consisted of common and more routine police tasks of a tragic or distressing nature, e.g., traffic accidents, handling cases of severe violence, suicide, homicide, child neglect and abuse, and making death notifications. Compared to a similar Danish study conducted three decades ago, the experiences of CI appear to have a continuing and general quality over time. The CI categories are further comparable to police-specific trauma event categories identified in other countries. The findings highlight the importance of recognizing routine police assignments as potentially distressing and emotionally burdensome, and they underline the importance of focusing prevention initiatives on the accumulation of psychological strain in police work due to various CI experienced over time.