İs it correct?

İnstalling camera everywhere in the public domain is not proportional in the fight against crime just because the event is clear and apparent in public domain.

This sentence is not particularly clear.  (You do not say to what the first part of your sentence is "proportional".)  Perhaps you wanted to say something like:

Although having public video surveillance may help in the fight against crime, it is not clear that its benefits outweigh its deficits.