Various factors affect the degree of mass crime of an environment, including social, economic, and physical factors. The purpose of this research is to investigate the role of the physical components of an environment on mass crime rate. In this regard, open spaces between residential complexes were selected as the case studies and based on five outdoor patterns including linear pattern, dispersed pattern and open central courtyard pattern and closed central courtyard pattern, as well as molecular pattern in five residential complexes, was selected in Shiraz city. The analytical tool in this research is syntactic theory, and analyses were carried out using Depthmap software. In this study, four indicators of "physical accessibility", "visual accessibility", "local access" and "universal access" as a research framework were formulated and case studies were analyzed based on them. Finally, an optimal final pattern with the lowest probability of mass crime is presented and the corresponding solutions are explained. The results of the study on the effect of outdoor design on providing space security with regard to the spatial access indicators showed that among the five proposed patterns, the central yard pattern and the closed central courtyard had the largest rate of space security. Other patterns including dispersed, linear and molecular patterns are in the next positions, respectively.
