"criminalisation is a complex and dynamic process of catgorisation and discrimination rather than a static practice of deductive reasoning from premisies set by legal definitions. Discuss."
First thing I noted is that it says "Discuss" - thus, there should be no right or wrong answers and as this is your first assignment, they're probably just trying to gauge your level of thinking.
From the above, I would think the question simply asks us to consider the process of criminalization. According to the prompt, it should be a complex and dynamic process involving hands-on actions (criminalization and discrimination) as opposed to purely deductive reasoning based on strict legal definitions.
Now that we've rephrased the question, it should make more sense. We could easily discuss any criminal case or issue that particularly stands out. A good one might be trial by jury, where the jury system itself is living proof of the courts departing from purely "deductive reasoning" based on "strict legal definitions" - there are now many other factors in play as well and certainly "discrimination" would be one of them.
There are the usual ways of approaching this problem - agree/disagree/qualify + define the terms (don't forget to define criminalization!). It's up to you now to decide which angle you would like to take and to defend it (aka provide examples).