This paper presents the methodology for Concealed Weapon and Explosive (CWE) detection using Ultra Wideband (UWB) radar. The framework of the approach is based on the study of the Late Time Response (LTR) of the complex human-explosive object which occurs when the illuminating signal is characterised as UWB. The LTR is analysed using methods for extraction of its natural resonant frequencies which constitute a unique signature. Therefore it is investigated if the explosive or grenade resonant frequencies can be retrieved by the human-grenade LTR.