Brain-Scan Lie Detection Rejected By Brooklyn Court

blair1q writes "A judge in Brooklyn has excluded Functional Magnetic Resonance Imaging (fMRI) lie-detector evidence from a trial there. However, the decision will not set a precedent, as it was made without even conducting a hearing on the method's validity, but on the principle, argued by the defense, that 'juries are supposed to decide the credibility of the witness, and fMRI lie detection, even if it could be proven completely accurate, infringes on that right.' That principle can be tested in later hearings, such as one scheduled for May 13, 2010, in Tennessee; in this case, the defense wants to use fMRI evidence it has already collected to prove its client is innocent. fMRI has been shown to be 76-90% accurate. That number seems significantly larger than the rate of false convictions."

Comments

Because they are unreliable.

[Mekkah]

They don't tell you shit, I've taken a couple of them for government work and it depends on the person, and their ability to concentrate. You can easily get false positives and easily beat it if you have the right mindset.

The Interesting Question is...

[cheesethegreat]

Here is the interesting hypothetical:

Assume this lie-detector is right 80% of the time, and that its success/failures are randomly distributed (e.g. not associated with socio-economic background).
Assume also that false conviction rates are at 21% (so only 79% of convictions are correct), and that there is substantial evidence that this is not evenly distributed (e.g. that false convictions are associated with low socio-economic status).

Would you be willing to entirely replace the system of jury trials with trial by lie detector?