Crime is a necessary evil. The interests of criminologists include the study of nature of crime and criminals, origins of criminal law, etiology of crime, social reactions to crime, and the functioning of law-enforcement agencies and penal institutions.

It can be said that broadly criminology directs its inquiries along three lines: first, it investigates the nature of criminal law and its administration and conditions under which it develops; second, it analyses the causation of crime and the personality of criminals; and third, it studies the control of crime and the rehabilitation of offenders.

Whether criminology is a science? 

Several times the question arises whether criminology is a science? No universal answer to this question could have been given till today. Some criminologists treat it as a science while others do not. 
Science is a systematic study of any subject. In, it relationships are established between causes and consequences. 

Science has three characteristics – 
(a) A systematic study of any subject
(b) The capacity to establish relationship between causes and consequences. 
(c) The certainty and universality of principles. 
On the basis of the above characteristics, Michael does not consider it as science and according to his opinion, it cannot be science in any way.  

Scope of study of Criminology

The following things are studied under criminology 
1 What is a crime? 
2 Why crimes are committed? 
3 Why the internal conscience of a man becomes criminal? 
4 How one can reach from the point of crime to criminal? 
5 How crimes can be prevented? 

Importance of Criminology

The following are the main causes of the study of Criminology 

(a) The criminology clears the way of study of the social system. 
(b) It suggests the ways of elimination of criminal instincts in the society 
(c) Criminology tells the ways of bringing stability in human values. 
(d) It tries to reform the criminal 
(e) This system of study becomes helpful to the investigation officer in reaching from the point of crime to the criminal.  
(j) Crime is a necessary evil and an ailment. Criminology suggests the ways and means of checking this evil. 
(k) Criminology tells the effective methods by which the crimes can be controlled so that peace and order may be established in the society. 
(i) The Spirit of social security is created by the study of criminology.