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I am not a lawyer and I don't know how federal court works so I'm genuinely curious: FBI forensic "scientists" are essentially always lying on the stand -- not

by wfo 11y ago

I am not a lawyer and I don't know how federal court works so I'm genuinely curious: FBI forensic "scientists" are essentially always lying on the stand -- not out of malice or intentionally, but because their techniques do not have nearly enough accuracy to honestly present the results that they present. There is plenty of evidence for this, this article and others. Anything except DNA is essentially a fortune teller reading a palm. So why does every single defense attorney in the nation (including public defenders) not spend hours on this particular fact any time an FBI forensic scientist testifies in a case? And essentially make having forensic evidence from FBI crime labs a huge liability and unusable in court? Do they try and people just believe the FBI anyway?

TrevorJ 11y ago
>Anything except DNA is essentially a fortune teller reading a palm. DNA evidence has been somewhat problematic as well, though mostly due to improper/non existing lab standards: https://www.utexas.edu/courses/bio301d/Topics/DNA/text.html https://www.utexas.edu/courses/bio301d/Topics/DNA/text.html
LordKano 11y ago
In the earlier days of DNA analysis, they routinely overstated the certainty of matches. They were testing too few loci for the kind of results they were claiming. Matches that were called something like one in 8 billion were sometimes more like one in 2 million. In a city the size of New York, that's far less certain of match than they stated.
- Lawtonfogle 11y ago
  It is also bad statistics. The expert points out that it is 1 in a million. The jury will think this means that there is a 99.9999% chance this guy is guilty. But how it works (assuming the DNA is the only evidence to connect this guy to the crime) is that in a city of 100 million, there are 100 possible people who would match, so the actual chance this one guy who was found by DNA match is actually the guilty one is only 1%. People are willing to convict if given 99.9999% certainty. But who would be willing to convict with only 1% certainty?

by wfo 11y ago

TrevorJ 11y ago

>Anything except DNA is essentially a fortune teller reading a palm. DNA evidence has been somewhat problematic as well, though mostly due to improper/non existing lab standards: https://www.utexas.edu/courses/bio301d/Topics/DNA/text.html https://www.utexas.edu/courses/bio301d/Topics/DNA/text.html

LordKano 11y ago

In the earlier days of DNA analysis, they routinely overstated the certainty of matches. They were testing too few loci for the kind of results they were claiming. Matches that were called something like one in 8 billion were sometimes more like one in 2 million. In a city the size of New York, that's far less certain of match than they stated.

Lawtonfogle 11y ago
It is also bad statistics. The expert points out that it is 1 in a million. The jury will think this means that there is a 99.9999% chance this guy is guilty. But how it works (assuming the DNA is the only evidence to connect this guy to the crime) is that in a city of 100 million, there are 100 possible people who would match, so the actual chance this one guy who was found by DNA match is actually the guilty one is only 1%. People are willing to convict if given 99.9999% certainty. But who would be willing to convict with only 1% certainty?