one who is trained in the field of criminology. Also, one who studies crime, criminals, and criminal behavior.

One who brings objectivity and method to the study of crime and its consequences; also see criminology

A criminologist is often defined as someone who studies the aetiology of crime, criminal behavior, types of crime, and social, cultural and media reactions to crime. The term criminologist generally refers to someone who does scholarly, scientific and professional study concerning the aetiology, prevention, control, and treatment of crime and delinquency, measurement of crime, law enforcement, judicial, and correctional systems. It may also include the study of victims of crime.

a specialist in criminology