Re: DNA limitations.
picky said:
AJ = Red
As I mentioned, evidence can be mishandled, planted or faked and honest mistakes can be made.
How can an abundance of semen and/or blood DNA be mishandled, planted or faked so that you have a false positive?
It could be accidentally swapped with evidence from a different case. Now that would mean that the person was still guilty but of a different crime. They could be found guilty of murder when all they really did was something like robbery.
Or an overtired lab technician could accidentally process the suspect's sample when he/she thought they were processing the crime scene sample. The report would then show that the crime scene sample matched the suspect's sample when it really didn't.
I would guess that for every scenerio I can imagine there are even more.
picky said:
The reason O.J. got off was because his lawyers were able to make the overwhelming DNA evidence questionable. Why can't it be true that an over zealous prosecuter could succeed in making questionable DNA evidence look more legitimate? That's how my example could be transitive.
How was the DNA questionable? It could not have been planted because how would Marc Furhman get a hold of O.J’s blood. How can you explain away the cut on his hand, the shoe print, the gloves, and his strange disappearance? Johnny C. threw up a Hail Mary knowing that the African American jurors would want to strike back at the past injustices of the LAPD. O.J. Simpson was as guilty as sin and everyone in the courtroom knew it!
I didn't say the DNA was questionable. I said the defense made it look questionable by clouding the evidence with unrelated issues.
My point is that O.J.'s laywers were able to win in the face of overwhelming DNA evidence by raising just enough doubt to get him off then why can't it also be possible for a skilled prosecutor to be able to take circumstantial DNA evidence and convict an innocent person.
For example, a friend of mine has been shot and killed and they find my DNA at his place. It's my friend and I've been to his house recently so of course my DNA might be there. Now let's say that the police are under public pressure to find the killer so they charge me because they have DNA evidence. The prosecutor, under pressure as well, takes that DNA evidence and makes me look like a killer using the same method that O.J.'s lawyers did.
DNA evidence is only as good as the weakest link in the chain - people. DNA evidence is gathered by people, handled by people, processed by people, interpreted by people, presented by people and judged by people (the jury).
I think DNA evidence will make it easier to find those responsible but the systems around it are falable.