Massad F. Ayoob (born July 20, 1948) is an American firearms and self-defense instructor. He has taught police techniques and civilian self-defense to both law enforcement officers and private citizens since 1974. He was the director of the Lethal Force Institute in Concord, New Hampshire, from 1981 to 2009, and now operates his own company. Ayoob has appeared as an expert witness in several trials. He served as a part-time police officer in New Hampshire since 1972 and retired in 2017 with the rank of Captain from the Grantham, New Hampshire, police department.