Of moos and clucks-the myth of FTIR identification By: Frederic Whitehurst, J.D., Ph.D. [1] OK, so we will now discuss moos and clucks. Which is the basis for the problem with Fourier Transform Infrared Spectroscopy (FTIR) in forensic science. [2] If you close your eyes in a stock yard you can’t tell what moo came […]
Zero is not a valid data point for calibration purposes
When the quantitative measurement really matters to determine guilt, we have to understand how that measurement is achieved. In the case of the analysis of biological samples that are tested, quantitation of an unknown is derived from a calibration curve. The proper construction of the calibration curve is a crucial component of quality control. It […]
Guest Blog Post From Dr. Frederic Whitehurst PhD JD: Circuitous thought-the myth of reliable and valid marijuana identification in the courtroom
Circuitous thought-the myth of reliable and valid marijuana identification in the courtroom By: Frederic Whitehurst, J.D., Ph.D. [1] As scientists we all agree that the hallmarks of science are validity and reliability. What do we mean by that? Well, the government scientist has to agree that his method of answering a question put to him […]
Guest Blog Post From Dr. Frederic Whitehurst PhD JD: On sampling when testing multiple packets
Sampling Crime: On sampling when testing multiple packets By: Frederic Whitehurst, J.D., Ph.D. [1] If we accept that forensic crime laboratories are completely overwhelmed, understaffed, underequipped, and exhausting environments in which to function, we see reality. Despite political rhetoric to the contrary, there has been little, if any, relief for those folks in crime labs […]
Guest Blog Post From Dr. Frederic Whitehurst PhD JD: Forensic Science “Matches”-The Case of Black Powder
Forensic Science “Matches”-The Case of Black Powder By: Frederic Whitehurst, J.D., Ph.D. [1] While reviewing case opinions in criminal matters involving forensic examinations one is often presented with various adjectives of comparison such as “matches,” “consistent with,” and “identical to.” Counsel seeing these adjectives in forensic reports may be elated if legal theories are supported […]
Guest Blog Post From Dr. Frederic Whitehurst PhD JD: “Matches” An Over inference of Data? A Giglio Obligation? The case of Paint Examination
“Matches” An Over inference of Data? A Giglio Obligation?: The case of Paint Examination By: Frederic Whitehurst, J.D., Ph.D. [1] and Darlene R. Brezinski, Ph.D.[2] Forensic chemical analyses of complex matrices such as plastics, paints, or paper products, may lead to inconclusive results without analysts or reviewing counsel aware of the failing of the analyses. Complex […]
Quality Control in GC-FID: Teaching the machine right from wrong
It is shocking but very true statement that most sophisticated instruments such as a Gas Chromatograph (GC) with various detectors whether it is a mass spectrometer (MS) or flame ionization detector (FID) when produced and manufactured are incapable of producing meaningful results “straight out of the box.” These machines have to be “taught” what it […]
Guest Blog Post From Dr. Frederic Whitehurst PhD JD: Mr. Fletcher vs. Mr. Daubert A Journey into the Surreal
Mr. Fletcher vs. Mr. Daubert: A Journey into the Surreal By: Frederic Whitehurst, J.D., Ph.D. Many a defense attorney has looked in amazement at the courtroom “identification” of Cannabis Sativa L. by a law enforcement officer sporting a gilded pot metal badge and a high school diploma who has written a report that would […]
The myth of specific identification of Marijuana in criminal court Part 7: Is there a better way to test for marijuana?
Throughout this series of posts we have examined the Thorton-Nakumura protocol that is used throughout the United States for the prosecution of illegal possession marijuana. A fair examination of the question reveals that there is no validity to the notion that the 3 test regimen produces a valid conclusion that the unknown examined in fact […]
The myth of specific identification of Marijuana in criminal court Part 6: Is the combination of all three tests create a “good” testing scheme?
The modern day prosecution for the unlawful possession of marijuana is based upon a three test regime involving microscopic morphological examination, modified Duquenois-Levine colorimetric testing, and Thin Layer Chromatography. Each of these three tests are non-specific for THC which is the pharmacodynamically active ingredient which makes marijuana illegal. The question becomes is this three test […]
The myth of specific identification of Marijuana in criminal court Part 5: What is Thin Layer Chromatography? Is it a “good” test?
All prosecutions for the unlawful possession of marijuana requires as an essential element of the crime for the government to advance proof that the unknown submitted for testing is in fact marijuana (contains THC). Can the government actually do that based upon its typical testing method? In this series of posts we are going to […]