Abstract. Today, software security is an issue with increasing importance. Developers, software designers, end users, and enterprises have their own needs w.r.t. software security. Therefore, when designing software, security should be built in from the beginning, for example, by using security patterns. Utilizing security patterns already improves the security of software in early software development stages. In this paper, we show how to detect security patterns in code with the help of a reverse engineering tool-suite Bauhaus. Specifically, we describe an approach to detect the Single Access Point security pattern in two case studies using the hierarchical reflexion method implemented in Bauhaus.