Reality is reality. People may have their own PERSPECTIVE and PREFERENCE, but reality does not change. It is not dependant on perspective and is not affected by it either. What most people make the mistake of doing is equating perspective and preference with some form of reality. It is not, it simply your like or dislike based on facts that are singluar to you and only you.
Just because a group fo people are incapable of coming to a non-contradictory truth regarding whatever the question is, does not invalidate reality, it simply shows the inability of some humans.
Does that mean that we're all not ever capable of understanding reality?
No, we do all of the time, especially in mathematics and physics (see my blog post on the subject of subjectivity at johngalt.joeuser.com). The problem is that the way we judge the legal system and a crime is flawed and thus it is impossible with a contradictory system to ever arrive at a non-contradictory solution to a question.
The first thing that has to happen is you have to start from a non-contradictory value system. Once you do that, then everything else falls into place.
Objectivism is one such system. It is the only system so far found that is completely non-contradictory. It holds life as the highest ideal, and freedom as the requirement for life to flurish. It defines a crime as physical harm. No other act is a crime. Thus it becomes very easy to judge if someone is guilty or not (especially with DNA evidence now) because it's a matter of "was their physical harm?" If yes, then their guilty, if no, then they aren't. Because of the simplicity of this litmus test, it takes away perspective, it takes away intent or excuse and as a result, gets to the truth in all of it's perspectiveless glory.
But make no mistake, that doesn't mean that everyone is required to be an atomiton believing whatever the majority says is right. On the contrary, your free to act and do whatever you wish so long as you don't harm another (without permission, or you're acting in defence of others or yourself). This is the beauty of freedom. Preference is yours, it is non-contradictory and has nothing to do with reality other than the reality that you like Apples more than oranges. Your preference and perspective do not harm anyone else, and if you harm yourself because of it, you're free to do that too.