Science is a general term that describes the collection and organization of ideas and understanding them through series of explanations, tests and experimentations. On the other hand a brief definition of criminology from Merriam Webster is "the scientific study of crime as a social phenomenon, of criminals, and of penal treatment".
Criminology is generally a method of identifying a crime. In doing so, you should be able to understand the concepts of it which includes the nature, causes, outcomes, extent, of the crime and the person involved with it. Without applying the science, a crime is not solvable.
Criminology can be considered as an applied science since we are using the basic sciences and transform it into practical applications. You can't determine if a white powder thing is cocaine unless you apply your chemistry knowledge to it. DNA testing for rape cases is a very effective measure in dealing in identification of suspects. Speed, velocity and acceleration are also used in dealing with hard cases. And finally, we like it or not, we apply mathematics on crimes.