Assuring compliant business processes is an important task of business process management, which is commonly supported by the use of business process models. As every compliance rule corresponds with a typical structure, the detection of those corresponds to a pattern matching problem. More specifically, we encounter the problem of subgraph isomorphism. In this paper we propose an automatic business process compliance checking approach that relies on a subgraph isomorphism algorithm and that is suitable for process models in general. As common subgraph isomorphism is a problem that can only be solved in exponential time, we use an algorithm that simplifies the problem through pre-processing. This makes the isomorphism solvable in polynomial time. With the approach, we aim at supporting decision makers in business process compliance management.