How weak DNA evidence railroaded—and then rescued—Amanda Knox

[DainBramaged]

If you watch crime dramas, you'll be forgiven for the impression that DNA evidence makes an airtight case. And if you do have that impression, you might be confused about the internationally famous case of American Amanda Knox, convicted of murdering her British roommate in Perugia, Italy in 2007. After all, the prosecution's case was based on DNA evidence; Knox's genetic fingerprints were found by Italian police on the handle of a kitchen knife, which also had the victim's DNA on the blade.

But not all DNA evidence is created equal—and Knox walked free last week from an Italian jail after scientists savaged the forensic evidence against her as being wholly unreliable. How did DNA analysis go so wrong?

To understand the problems with the Knox case, we drew on the extensive real-world genetics experience of the Ars science staff and spoke with Dr. Lawrence Kobilinski of the John Jay College of Criminal Justice in New York. Kobilinski has seen the DNA test results from the Knox case and helped walk us through the reasons that DNA evidence isn't always as airtight as it sometimes looks on TV.

DNA analysis amplifies a tiny bit of DNA into millions of copies, but this amplification process can lead to problems if it's not carefully managed. The results of this process don't speak for themselves—interpretation is always required—and the interpretation of DNA analysis became a decisive problem for Amanda Knox. In the end, terrible crime scene management and an unjustified certainty about DNA evidence on the supposed murder weapon led to a murder conviction that collapsed on appeal.

http://arstechnica.com/science/news/2011/10/how-weak-dna-evidence-railroadedand-then-rescued-amanda-knox.ars


I have no opinion on this article, nor do I care about the case. My life is more important. I just thought it would be fun to stir the pot again, besides, there's nothing new on the Charlie Sheen front........

[Hepburn]

1. DNA is NOT foolproof!

Especially for African Americans that have close ties to their origins.

DNA is worked on a mathematical comparison ~~ and because the sampling of AA's of close origin to Africa is not as diverse as needed, there can be some very odd results. Case in point: Two AA MD's both tested as the father of the child of a nurse where they were both doing residencies at the same time and had sexual intercourse with her during the period of conception.