A person who is skilled in, or practices criminology(noun)
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Use "criminologist" in a sentence
"He became well known as a criminologist and also as an advocate of laws for the safeguarding of the public health and against adulteration of food."
"He returned to the library, where he lost himself in the rare old volumes of Grimsby's life collection: the criminologist was a booklover and the hours drifted by as in a happy playtime, until the butler came to tell him the time."
"CBI has also contested a letter written by a so-called criminologist on the issue as malafide and gave a para-wise rebuttal of charges levelled against the forensic doctors who had conducted the post-mortem as well as DNA examination."