Nuclear, chemical and biological weapons are weapons of mass destruction used in non-conventional forms of warfare, and which were used mainly for military purposes. Due to an increase in terrorist activities, these agents are no longer used only for military purposes, but also for terrorist ones. The understanding of CBRN weapons is no longer limited solely to military agents and the means of their delivery, but has been expanded to include related materials, equipment and technology for the design, development, manufacturing or use of CBRN weapons. Criminal investigation in CBRN conditions is a multidisciplinary area requiring trained teams, preparation, logistics, special safety measures and cooperation with the experts from different specialty fields in order to properly and safely gather and analyze evidence. Criminal investigation in CBRN conditions can be divided into three sub-domains: contaminated crime scene investigation, gathering and analysis of traditional evidence in the contaminated area and the gathering of CBRN evidence and its identification and characterization. The aim of this paper is to show specific properties of a contaminated crime scene, as well as to provide an overview of methods and techniques used in a CBRN crime investigation.