Scientists Find Way To Combat Forged DNA 45
An anonymous reader writes to tell us that while scientists may have learned how to forge DNA, it appears that a group of Israeli scientists has created a DNA authentication method that is able to distinguish between real and faked DNA samples. "The new process was tested on natural and artificial samples of blood, saliva and touched surfaces, with complete success, Nucleix said. It also identifies 'contaminated' DNA that has been mixed with two or more samples."
Plausible denability? (Score:5, Insightful)
So if I make fake DNA of myself and throw around a crime scene then I can use this method to prove I wasn't there?
methylation? (Score:1, Insightful)
pff That test probably checks for methylation or something like that. Usually PCR'd DNA is not methylated, also material from PCR might have mistakes in the DNA, especially when a non-proofreading enzyme was used to amplify the fake DNA
Re:Plausible denability? (Score:5, Insightful)
No (And spanking the monkey is not "fake DNA")
All it does is provide doubt to the evidence. One cannot prove a negative ("I wasn't there"), which is why we assume innocence, and guilt must be proved beyond REASONABLE doubt.
To prove you "weren't there" you would have to have an alibi; evidence you were somewhere else.
Wrong - not useful to prove premeditation (Score:3, Insightful)
Wrong - not useful to prove premeditation
"If someone tries to spoof the existing test and they don't guess right in how to spoof it ... then it sort of nails them for premeditation of the crime."
Only if the crime you are talking about is framing someone, rather than the person being framed. Detection of fabricated evidence and contamination of evidence is useful as a defense against DNA evidence, it's not useful to law enforcement, unless the evidence was fabricated by an unrelated criminal. Even then, it only rules them out.
First derivative: In terms of premeditation, the act would be to use the amplification technique to frame yourself, plant evidence at the scene, and then later use the detection method to prove the evidence was manufactured, thus implying you were the victim of a frame-up, rather than the real killer.
Second derivative: A premeditated use of self-incriminating fabricated evidence could use the method as a positive assertion test to ensure that the fabrication would be caught immediately, if it was a standard cross-check, or at trial, if it wasn't. Use by law enforcement in order to manufacture a frame would be as a negative assertion test, to verify that the framing material would pass inspection at trial later, when it was attempted to be used by the defense, to create manufactured evidence which could be successfully used in a frame-up.
So in reality, the framing technique brings into question DNA evidence, and the anti-framing technique brings into question DNA evidence.
-- Terry