The following was written by Dr. Clifford Spiegelman, Distinguished Professor of Statistics at Texas A&M and one of the program leaders for the 2015-2016 SAMSI Program on Statistics and Applied Mathematics of Forensic Science.
Imagine having a nightmare where nearly all evidence presented in courts was seriously misrepresented. No, not a nightmare about someone accused of being a witch, but a more current trial. Say the defendant is accused of rape or murder and all the scientific evidence presented was seriously misrepresented and biased toward the prosecution. It would not be a pleasant dream, but it is today’s reality, and that is worse than a nightmare as it is real. Within the last months the FBI has admitted to over representing the importance of hair matches for decades. Prior to that in 2007 CBLA or comparative bullet lead analysis was another procedure used for decades where the FBI admitted to overstating the importance of a match.
Forensic science is inherently a field that uses data (patterns, pictures, etc.) to link suspects to crimes. Unfortunately, the use of formal statistical methods or even statistical or mathematical thinking is uncommon.
That is where you can help. There is a dearth of persons, as in way to few mathematical scientists, that are aware of the issues.
What are the issues?
Well one can read the summary of the 2009 NRC report “Strengthening Forensic Science in the United States: A Path Forward” to get a good overall view. Here are some of my recent consults: A defendant was charged with indecent contact with a minor. The minor had chlamydia but the defendant did not and was not treated for chlamydia. What is the probability? In another case a convict has been in jail for 40 years largely based upon hair and fiber evidence. The hair evidence was inconclusive. That is the crime lab hair examiner testified that there were both similarities and dissimilarities between the pubic hairs found at the scene and on the defendant. Subsequently some inconclusive results (not the case in question as the evidence has gone missing) have been investigated using DNA. What are the odds that an inconclusive microscopic hair analysis has a DNA analysis that excludes the defendant? It is more than ½.
The opening workshop will look at various forms of traditional pattern evidence. These include fingerprints, firearm/toolmarks, shoeprints etc.. Help become part of the birth of taking forensic science from oxymoron state to a real science.
The opening workshop program can be found here. Read more about the overall program here, and if you want to learn more about forensics before the opening workshop, consider attending a special tutorial a few days before the big event begins.
Please join us. You can make a difference to the legal system and make our country a more just place.