He worked at the Law Institute of Moscow, first as head of department and then as director. He made research at the Institute of the Rule of Law of the USSR Academy of Sciences, at the Union Institute of Legal Sciences. During 1929-1935, he worked as head of the criminal statistics sector of the Central Statistical Office of the USSR, head of the statistics department of the Main Police Directorate ofthe USSR NKVD. From 1963 until the day of his death, he led the sector at the Union Institute for the Study of Causes and Measures for the Prevention of Crime at the USSRProsecutor's Office. He has published over 250 scientific works and books on the general part of criminal law, papers devoted to the scientific and practical analysis of the principles of the criminal legislation of the USSR and the union republics, as well as the Criminal Code of the RSFSR of 1960. Alexei Gertzenzon participated active ni hte elaboration of the principles of the penal legislation of the USSR and of the union republics in 1958, as well as of the penal codes of the union republics. Among Alexei Gertzenzon's works are crime prevention studies - Criminology. A valuable contribution to the science of criminal law and the history of political doctrine is his work on the theories of criminal law of eighteenth-century French thinkers - Marat, Voltaire and Robespierre.