The top 2 problems seen with Gas Chromatography BAC results The testing method used most frequently in blood based Blood Alcohol Content (BAC) analysis in the United States is called headspace gas chromatography (GC) with flame ionization detector, using wall coated open tubular capillary columns. The process analyzes chemicals without decomposing them. The GC […]
Stereoselectivity matters in methamphetamine: The Science of Breaking Bad cook makes both D and L forms of meth
Methamphetamine analysis comes down to the stereoselectivity capabilities in the crime laboratory. Stereoselectivity is crucial in a crime laboratory. The ability of an analytical chemistry device to be specific to a type of a form of drug is key. Stereoselectivity is one of those key functions. Even the venerable workhorse of analytical chemistry in a crime […]
Standardized Field Sobriety Test and Age: 40 is the new 65
Standardized Field Sobriety Test and Age: Why At Age 40 You Are Over the Hill The Standardized Field Sobriety Tests have been used since the 1980’s to aid officers in the field in their decision-making to arrest motorists. But are they useful for all ages? When I turned 35, I started to get direct mailing […]
The ACS Hands-on Forensic Chromatography Class
The ACS Hands-on Forensic Chromatography Class There was a dream and the dream could best be stated thusly: Develop an expertise in that which interests you. learn, lean, learn, then do something totally counter-intuitive…. give away your knowledge for free to everyone and anyone who will listen. Become the proverbial Johnny Appleseed. People will love […]
DEA: If you can’t win by the science, win by changing the rules…
If you are a Star Trek fan, then you will remember Kobayashi Maru scenario. Wikipedia has a good description for you non-Star Trek fans. In Star Trek II: The Wrath of Khan, the simulation takes place on a replica of a starship bridge, with the test-taker as captain and other Starfleet members, officers or […]
Joshua Goldberg on Breath Testing Part 4
[Blog editor’s note: Joshua Goldberg of Pittsburgh, PA writes into us to share information about Breath Alcohol Content machines.] Additional Breath Testing Device Accuracy Limitations The main three issues with breath testing are: (1) an assumed partition ratio; (2) an assumed breath temperature; and (3) measuring devices not specific to ethyl alcohol. Breath testing […]
Joshua Goldberg on Breath Testing Part 3
[Blog editor’s note: Joshua Goldberg of Pittsburgh, PA writes into us to share information about Breath Alcohol Content machines.] III. THE ACCURACY LIMITATIONS OF BREATH TESTING DEVICES The courtroom must only permit sciences that accurately and reliably predict each defendant’s blood alcohol level. Yet, the twin assumptions of a 2100:1 partition ratio and a […]
Joshua Goldberg on BrAC testing part 2
[Blog editor;s note: Joshua Goldberg of Pittsburgh, PA writes into us to share information about Breath Alcohol Content machines.] THE HISTORY OF BREATH TESTING: TWO ASSUMPTIONS AND A QUESTIONABLE SCIENTIFIC PEDIGREE. Part 2 Assumption 2: Temperature of Breath Sample The second startling assumption occurs when the government couples the partition ratio with an assumed 34° […]
Joshua Goldberg on BrAC testing
[Blog editor;s note: Joshua Goldberg of Pittsburgh, PA writes into us to share information about Breath Alcohol Content machines.] THE HISTORY OF BREATH TESTING: TWO ASSUMPTIONS AND A QUESTIONABLE SCIENTIFIC PEDIGREE. Part 1 Modern breath theory as proposed by prosecutor’s testing emanates from a 19th Century formula discovered by British physician and chemist William Henry. […]
Stating the Obvious: There is Prosecution Bias in Most Crime Labs-the Colorado Department of Public Health and Environment Laboratory case study
Colorado Department of Public Health and Environment Laboratory crisis that concerns blood ethanol content by HS-GC-FID teaches us yet again the critical role that bias education plays in a crime laboratory. Everyone has bias. Bias is unavoidable. In fact, in certain contexts it is a good thing. Bias against strangers is what keeps kids from […]
How impossible courtroom testimony comes to be: the Colorado Department of Public Health and Environment Laboratory case study
Colorado Department of Public Health and Environment Laboratory crisis that concerns blood ethanol content by HS-GC-FID teaches us yet again the critical role that education plays in the training of analysts. People in the laboratory are just taught to press buttons and preform tasks. They are not experts. Anyone who has been in a courtroom […]
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