DNA, OH! DNA ! OH! DNA WHITHER ART THOU?

FOR THE PAST FEW DAYS THIS THREE LETTERS D . N. A have been taking centre stage in all our national newspapers and tabloids as well the electronic media. Everyone of us has been talking about it. Whether DSAI should or should not have voluntered to give his DNA, the advantages or disadvantages, the long and short of it all etc...
Just what is a DNA????DNA
DNA is an abbreviation from: Deoxyribonucleic acid.
It is a chromosomal double chain that exists in the nucleus of each living cell. DNA determines an individual's hereditary characteristics and can be used to distinguish and identify an individual from another person. This becomes critical when blood, hair, skin, or any other part of the body is used to prove one's involvement, or lack of involvement, in a crime scene.
Legal history proved that DNA tests have been used to release a convicted killer on death row who did not commit a crime, but debate continues over whether DNA evidence is scientifically certain enough to be admitted in trials. The current trend is to allow admission.
The debate currently in Malaysia in relation to the DSAI sodomy investigation viz. a viz allegation made pursuant to S.377 C, Penal Code is not the authoritativeness of the DNA but his reluctance to give consent to the taking of his DNA.
It should be noted that in so far as our evidence law is concerned, DNA is just another form of circumstantial evidence. Though it may be admissible in court as evidence, it is by no means conclusive proof so as to as render a conviction as to the guilt of the accused in a criminal trial.
Indeed the onus is very heavy on the prosecution relying on circumstantial evidence. Such evidence must point irressistibly to the guilt of the accused. If there are any gaps in it then it will not be sufficient. (PP v Lin Lian Chen [1992] 2 MLJ 561, Supreme Court)
So I really am puzzled why there are so much reluctance to volunter his DNA. Such evidence will still has to meet with other requirements of the law, as checks and abalance, to establish guilt especially in such sexual offence.