Hello, i'm Fernando.
I believe that you are trying to write a law article about the value of evidence in a criminal trial, witch is, in sumary, a discussion about the admission and the value of testimonial or theoretical evidence and physical evidence, such as blood samples, DNA, fingerprints, or, even, an audio tape; and, of course, how can one support the other.
I'm used to the US law and the commom law system, and i have a very good understanding about judge-made laws and precedents, but i never done anything specific about the UK law. So i'll need some time to do a respectful research and, of course, i'll follow the UK courts of law understandings.
I'm not gonna charge you my full price, because i'll enjoy to write an article about the UK law system, that said, it's gonna cost you something like US$45.00 or 40.00 euros.