Xiaoyu Alan Zheng is a Mechanical Engineer in Sensor Science Division of the National Institute of Standards and Technology (NIST). He has a B.S. and M.S. in Mechanical Engineering and focuses his research on objective measurements and analysis of 2D/3D firearm toolmarks. He served six years on the Subcommittee for Firearms & Toolmarks in the NIST OSACs where his contributions led to the development of three standards surrounding the implementation of 3D technologies in the forensic laboratory. He has led multiple successful National Institute of Justice grant funded projects for the development of the NIST Ballistics Toolmark Research Database (NBTRD) as well as research into population statistics for firearms. He is currently the chair of the Technical Advisor committee for the Association of Firearm and Toolmark Examiners (AFTE) and the co-chair of the Technical Working Group for 3D Toolmark Technologies (TWG3D2T). His primary focus is currently the development of the national Reference Population Database of Firearm and Toolmarks (RPDFT). This project seeks to provide forensic firearm examiners the ability to include objective similarity metrics and associated statistical statements of certainty with their court testimonies.