How do public administrators find information about the problems they confront at work? In particular, how and when do they reach across organizational boundaries to find answers? There are substantial potential obstacles to such searches for answers, especially in a system of decentralized governance such as the U.S. government. In this article, we examine the alternative mechanisms within the public sector that compensate for this dispersion of expertise, focusing on knowledge sharing across public DNA forensics laboratories. In particular, we propose that the emergence of informal interpersonal networks plays an important role in providing access to necessary expertise within a highly decentralized system. Our findings point both to the need for further research on knowledge sharing networks within the public sector as well as practical implications around the value of investments into facilitating the creation and maintenance of networks of practice.