We have written here before about DNA in several posts. In the case of mixed samples that come from true unknowns, the interpretation of the contributing source is far from an act of rigid mathematics, but truly requires interpretation. Wherever there interpretation, there is a chance of getting it wrong. The Scientific Working Group on […]
DNA Interpretation: The Prosecutor’s Fallacy
We have written here before about DNA in several posts. DNA is a very power tool is used correctly. It can free the falsely accused. It can also be used to condemn a man to death. Often times it is incorrectly reported and its value and relevance can also be extrapolated to beyond what the […]
Williams v. Illinois: The Confrontation Clause Rights in light of modern forensic science
On December 6, 2011, the Unites States Supreme Court heard argument in the case of Williams v. Illinois. The transcripts of the oral argument can is available on the Supreme Court of the United States website. Some information so you can understand the facts and the subsequent analysis that I offer: Summary of the Facts: […]
GC consumables and preventive maintenance
Lots of prosecutors and police scientists like to present the Gas Chromatograph (GC) and its results as totally infallible, not subject to interpretation, and never wrong. While GC technology is good (in fact if the analysis is conducted on a stable and properly maintained and installed instrument using a validated method with a well-trained and […]
How the GC-FID arrives at a quantitative result: Auto-integration versus Manual Integration
A frequently asked question on the listservs that I belong to basically asks the following question: In GC-FID use to quantify Blood Alcohol Content where EtOH is the target analyte, how does the machine arrive at the reported number? The machine is called a Gas Chromatograph with a Flame Ionization Detector (GC-FID). Typically the sample […]
A collosial waste of taxpayer money all in the name of forensics
I have seen a lot of government waste all in the name of forensic science, but this one is utterly foolish. It needs nothing but it’s straight fact reporting… Flashy $330,000 DNA Bus Bought by County Designed by the company that built Dr. Oz’s jumbo bus, the vehicle will collect DNA samples and serve as […]
The Coalition against Coelution
I saw this idea on the Restek Blog and thought it was quite funny. So I took it and slightly tweaked it. I wanted to share it with you… Move over Occupy (fill in the blank movement)… I’m helping to start a new a new movement “The CAC” or The Coalition Against Coelution stands for […]
Discover Magazine features the dangerous side of arson investigation
This month’s (November 2011) Discover Magazine features as a main article “Up In Smoke” (in the print version) and “Spark of Truth: Can Science Bring Justice to Arson Trials?” (in the online version) that is an in-depth review of the struggle of bring science into the field of fire debris and explosives investigations. In this […]
New CODIS guidelines from the FBI draws criticism
We have blogged before on some issues in DNA and in terms of CODIS and the various DNA databases: DNA Contamination that is amazing! Another example of flat out bad forensic science: Bad DNA results Bayesian Based Metrology and DNA What constitutes a “match” in forensic science? Physical evidence is often the most important evidence Now […]
Born on Date– Not Just for Beer But Gas Cylinders Too
Beer Born On Date Everyone wants to eat fresh food as opposed to stale food. No one wants to drink skunked beer. So, we have born-on dates on certain foods and foodstuff. This allows us to judge whether or not we want to accept it and drink/eat it. Carrier gas purity is a big issue […]
Emerging technology at the airport: Mass Spectrometry in the Hands of TSA
GE EntryScan is a type of newer technology EntryScan is the result of a successful five-year partnership between GE, the Pennsylvania State University Gas Dynamics Laboratory and the FAA/TSA. This research effort was based on the concept of understanding the natural airflow around the human body. In April 2003, the TSA confirmed that the EntryScan […]
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