The U.S. National Institute of Standards and Technology (NIST) is developing a comprehensive set of standard test methods and associated performance metrics to quantify key capabilities of emergency response robots. These test methods address responder-defined requirements for robot mobility, manipulation, sensors, energy, communications, operator proficiency, logistics and safety for remotely operated ground, aerial, and aquatic systems. The objective is to facilitate quantitative comparisons of different robot models based on statistically significant robot capabilities data, captured within the standard test methods, to guide purchasing decisions and understand deployment capabilities. The test methods also support operator proficiency training and foster development and hardening of advanced mobile robot capabilities. The process used to develop these test methods relies heavily on robot competitions to refine proposed test apparatuses and response robot evaluation exercises in responder training facilities to validate the test methods. The resulting test methods are being standardized though the ASTM International Standards Committee on Homeland Security Applications; Response Robots (E54.09). This work has been predominantly sponsored by the Department of Homeland Security (DHS), Science and Technology Directorate, Office of Standards; with substantial support by the Department of Justice (DOJ); NIST's Office of Law Enforcement Standards; Army Research Laboratory (ARMY-ARL); Joint Improvised Explosive Device Defeat Organization (JIEDDO); and Defense Advanced Research Projects Agency (DARPA). This work is conducted in collaboration with many more organizations world-wide, civilian and military, who help develop, validate, and use the resulting standards.