the aim of this research is to identify and characterise the main critical incidents experienced by the portuguese criminal investigation police officers and the related stress reactions, to organise a critical incidents intervention program to support those police officers. the data was collected using the critical incidents questionnaire for criminal investigation police (manuel & soeiro, 2009) through 255 individual interviews. the participants described two critical incidents involving operational work, firearms, difficult/violent individuals, evident human suffering and car accidents. participants identify as symptoms, cognitive, emotional and physical reactions. changes in the organisational policy, psychological intervention and increase social support were suggested to avoid critical incidents impact.