This is the first phase of the validation and adaptation of the questionnaire of environmen­tal observation for the space and environmental analysis of the homicide in Bogota. This work was made base on the Environmental Observation Inventory (Meeks, Perkins & tay lor, 1992), the homicide, the relations between environment and crime, which were the ele­ments that account for the inicial observation instrument. For the pilot study it was se­lected Kennedy (non-probabilistic sample) area and 20 places inside with bodies of homi­cide victims. The level of reliability between observers was 0.95. The instrument has 76 items in four scales of environmental observation, mess, territoriality, activity routine and defensible space.