Public safety communications provide effective communications amongst the first responders and victims in public safety scenarios. Device-to-device (D2D) communication is a technique that can be used to enhance network coverage in cellular networks. In this paper, we propose a novel D2D clustering scheme to expand cellular coverage for public safety communications. In the proposed scheme, cluster heads are selected from a group of public safety user equipment based on different metrics such as remaining battery power, SINR, number of discovered out of coverage devices and mobility. Each cluster head provides synchronization, radio resource management information and coverage to its cluster members. The simulation results demonstrate that our proposed scheme outperforms previous methods in terms of coverage percentage and energy consumption.