1998, served as the police chief of Connecticut, becoming the first Chinese head of state-level police in the United States. Prior to that, he served as Connecticut Commissioner for Public Safety, Director of Connecticut Forensic Laboratory and Chief Criminologist from 2000 to 2000. In 2006, he established Li Changyu Institute of Forensic Medicine. On September 20 13, he served as consultant of the Supreme People's Procuratorate Procuratorate Technology Information Research Center.
He identified several major cases in the world, such as the murder of President Kennedy, the Nixon Watergate incident, the Clinton sex scandal, the 9 1 1 incident, the murder of the wife of American football star Simpson, the forensic investigation of the Yugoslav mass murder, and the shooting in Lv Xiulian in March 19. Li Changyu has won more than 800 honors, including: the highest honor award in forensic medicine awarded by American Forensic Medicine Association-Outstanding Service Award in Criminal Field, Outstanding Achievement Award awarded by American Forensic Medicine Association, Lifetime Honor Award of International Medical Association, Outstanding Chinese Award in the World, etc.