i need to find the flaws of DNA evidence?

Question

there is some flaws that i already know like it can get contaminated in the evaluation process, it degrades on denim and its the same in identical twins. But there is another flaw that was on the news not too long ago. im trying to prove someone innocent. i know they are but there is some DNA that was planted at the scene. i know they are innocent but i cant give say anything. (its complicated) so if theres anyone that can help. thankyou

Answer 1

First, ask yourself HOW do I know this person is innocent? You have to seek hard evidence. You can't go on hunches, gut feelings and personal convictions along the lines 'I just know he wouldn't do it.'

Now to the DNA evidence. You do not, perhaps understandably, give sufficient detail to provide comprehensive advice. However, DNA profiling is pretty well water tight in its technology. If you doubt the results then your friend's solicitor could arrange a second analysis by an in dependant group.

Contamination is the greatest source of challenge. This could have occurred in the laboartory but I have to say that is very unlikely. A second test on the original material would help resolve this.

It could have been deliberate contamination before material reached the laboratory but that is not a failure of the DNA analysis in itself.

Then you have to consider how the DNA got where it did. Again this is not a failure of the DNA analysis. The best example here is semen on a vaginal swab. Clearly, that is not evidence of rape if consent is the issue. So, is there an 'innocent' explanantion for the presenece of the DNA?

You don't mention the match probability of the result. This is generally expressed with regards to the general population but there is a greater chance the DNA came from somebody else if blood related family members are considered.

Challenges are also made on procedure. This starts with the taking the samples all the way through to anlysis and presentation of results. Now-a-days, these procedures are well documented as part of comprehensive quality assurance management. If it can be shown that these procedures were not adhered to then this has enormous imoact on the signigicance and acceptability of the DNA evidence.

Answer 2

If you took 100 -Samples each of 2 races (meaning 100 x 2= 200 -Samples)

u wouldn't know which is from which. (The genetic segregation // distribution in the race profiles are the same(in all races). __ ( a.) )

There is not one single -Sample you can read the race from the DNA.

,, if u added 100 -Samples of chimpanzee DNA ,, we cannot tell the difference that the genome is not human. Neither can we pull out anything that looks "not natural" ,, (The distribution (difference between individual) AGAIN looks the same. __ ( b.) )


BUT ,, the individual cannot escape ,, that is unique ,, because of how he uses the 90% un-used space in the genome. The genetic garbage he throws away is his genetic signature. How he throws it and where. Garbage is inherited , but he re-arranges it and add some.



But , there's one thing u can tell from blood ,, looking for the negroid protein. Africaans have 1 extra protein than anybody else. That's why it first reads negroid or non-negroid ,, then comes the DNA profile.

If it 's negroid ,, we know he's human.

If he non-negroid ,, we don't know if he 's human or chimpanzee.


Hope this helps.

Answer 3

You would have to give more information.

DNA merely proves that genetic material from the person in question was at the point of collection, in rape cases it can prove who had sexual intercourse and in murder cases it can prove someone was at the scene. However DNA is stable and time is a flaw in terms of someone being somewhere. in rare cases DNA can be transfered by a second party if they came into contact with body fluids etc. There are cases of Chimeras who have diferent genetics in epithielial cells than in blood, often giving false negatives, however these are believed to be rare.

Lab contamination is strictly controlled through chain of evidence and is highly unlikely, but is always possible

Answer 4

If a blood sample has been planted at the scene there is the possibility that it was from a sample collected for medical purposes. There exists the possibility that the sample contained chemical(s) to stabilize it not found in raw blood. The link shows how evidence (including DNA) may be manipulated.

Answer 5

Some people have more than 1 set of DNA. On Discovery Health channel, they showed the case of a woman whose DNA did not match her 4 children. It looked as though she was not biologically related to her own children. They took more and DNA samples from different organs and continued to test. Finally, they found the DNA that matched her children. She has 2 sets of DNA.

Answer 6

How do you know that a DNA sample of the person was planted at the scene? Maybe its your "innocent" suspect that you need to question further.

Answer 7

The people of check for the DNA are a flaw, it was in the news a while ago that one of them didn't do their job properly.

Answer 8

and you think you'll get a sensible answer about a subject like that on yahoo?
Name your planet of origin here:.............

Answer 9

You need to talk to a specialist I think !!!

Answer 10

What you need to do is to do your OWN homework!