Little is known about the decision‐making processes of homicide detectives; this study is a first step towards understanding the inferential processes they engage in during the initial stages of an investigation. A card sorting exercise consisting of 20 crime scene photographs showing homicide victims in situ was designed to examine how detectives categorise and conceptualise homicide crime scenes. Forty homicide detectives were asked to ‘think aloud’ whilst categorising the crime scenes. Qualitative content analysis of the ‘think aloud’ accounts revealed detectives' intuitive ability to automatically make detailed inferences regarding the circumstances surrounding each homicide on the basis of available crime scene information (victim's sex, location, and method of death). A cycle of cognition was evident whereby detectives drew upon the contextual information available to generate hypotheses regarding homicide type (domestic, male brawl, and crime‐related) and derive inferences about victim–offender relationship, offender behaviour, motive, and whether the offence was spontaneous or planned. The detectives made 594 inferences of which 67% (N = 398) were accurate. The sorting exercise proved to be ecologically valid, with detectives reporting that they assessed and interpreted the homicide crime scenes, as they would in an actual investigation. The implications for police training and ‘offender profiling’ research are discussed. Copyright © 2013 John Wiley & Sons, Ltd.