My personal opinion and suggestion is that one should or can opt Criminology if one can arrange study material for the said subject. Unlike other subjects in this very group, Criminology does not demand a pure Law background. The main things are that how one can get good study material, one's interest in the subject and one's analysis and presentation of points that one has to present in ht exam.
You can surely opt Criminology without worrying that you do not have Law background.

__________________
"But screw your courage to the sticking place,
And we'll not fail." _Shakespeare, 'Macbeth')