Ask a Forensic Scientist

[Ajidica]

Okay. Its just considered to prejudicial as evidence even though the defense could cross the expert delivering the polygraph. Thanks.
Out of curiosity, do you know of any studies off the top of your head that show polygraphs are increadibly prejudicial?

EDIT: Yeah, I know insanity pleas are rarely used. It was just the best I could think of at short notice for hinging upon subjective testimony.

 

[nonconformist]

Not off the top of my head, but I do remember that it's actually about as reliable as chance; i.e guessing whether it's the truth or a lie.
http://www.usatoday.com/news/nation/2002-09-09-lie_x.htm

Other particular disadvantages are certain people aren't supceptible; issues with blood pressure etc. but more to the point, career criminals and sociopaths can easily bluff it.
Likewise, a normal human being could, if they fluff the "control" questions by artificially raising their stress symptoms.

Frankly, other methods of interview and interrogation provide better evidence.

 

[nonconformist]

You guys might be interested in this:

 

[ParkCungHee]

The chart leaves out the worst part: Juries now hold unrealistic expectations on the likelyhood of biological evidence.

 

[nonconformist]

Yer, we call it the "CSI effect"