Criminologist (noun)

1. A person who specializes in the study of crime and criminal behavior.
2. An expert in the field of criminology, which is the scientific study of crime and criminals.

Origin:

Late 19th century: from latin crimen "crime" + -ologist.

Examples:

1. Criminologists use statistical data and other research methods to study criminal behavior.
2. He was a renowned criminologist and had published several books on the subject.
3. The criminologist studied the causes of juvenile delinquency.
4. The criminologist's testimony was important in the court case.
5. The criminologist's research showed that poverty and unemployment were major factors in the rise of crime.