Introduction: When investigating traffic accidents and violent incidents the authorities need information about the psychophysical condition of the victims, therefore it is important the investigators and healthcare personnel cooperate effectively. Purpose: The theoretical part introduces the area of interprofessional relationships of nurses and the police officers/detectives. For the empirical part we obtained the data on the knowledge among emergency nurses regarding recognising and handling of material evidence, and evaluated the current cooperation of emergency units and the police in the cases where the investigation requires it. Methods of work: The questionnaires were distributed among the nurses in five hospital emergency departments and among detectives in eight police directorates. We compared their replies. Results: Nurses and detectives cooperate on numerous occasions, most often face to face and over the telephone. The nurses evaluated the cooperation more favourably than the detectives, who were to a larger degree of the opinion, that they are facing stereotypes in this kind of environment. The groups differ in the opinion as to the clarity of the instructions and guidelines for the handling of victims' clothes and shoes, and dangerous objects; however, they agree that the instructions are the clearest for the victims of rape. Both groups know the correct procedures for handling the clothes of patients, who are stabbed or shot in the torso, they also know the procedures for taking blood and urine samples. In handling foreign objects only a third of respondents knows the only correct procedure. The higher the knowledge of each group of professionals, the higher they evaluate their knowledge of procedures in emergency healthcare. Both groups feel they know the procedures well. There is a higher percentage of detectives who see the knowledge of proper collection and study of material traces as important. They also put much more importance on the need for accurate written instructions for the procedures of the healthcare staff in forensic examination, although more nurses estimated that they destroy forensic evidence during emergency procedures. Regarding the option of simultaneously carrying out the procedures, the groups do not differ – both believe that these procedures can be carried out side by side. Nurses believe that cooperation between the groups could be improved by written instructions for the common areas, while detectives believe that improvement could be best achieved in informal meetings. Discussion and conclusion: Nurses and detectives cooperate well, but would need common instructions and protocols.