In a series of posts, we are going to talk about Mass Spectrometry. Introduction-The different configurations and the Electron Impact process What types of mass analyzers are there? What type of detectors are there? What types of analysis can be done? How do you read the output? How do they come to a qualitative measure […]
Mass Spectroscopy for Lawyers Part 6: How do they come to a qualitative measure using software?
In a series of posts, we are going to talk about Mass Spectrometry. Introduction-The different configurations and the Electron Impact process What types of mass analyzers are there? What type of detectors are there? What types of analysis can be done? How do you read the output? How do they come to a qualitative measure […]
The Particular Witness Rule as established in Bullcoming v. New Mexico
SPECIAL EDITION NEWS FLASH: [Full Disclosure: I was one of the co-authors on the NACDL/NCDD amicus curiae briefs in the case of Bullcoming v. New Mexico. You can hear the audio of the oral argument here. I have waited several hours on purpose to post here in order to try to remain objective.] On September […]
Why evidentiary breath test machines are not regularly scientifically calibrated
One of my favorite movies is The Matrix. There is one scene that really jumps out to me. When Morpheous and Neo first meet. Morpheus shows Neo two pills: a blue and a red one. If Neo chooses the blue pill, he will wake up in his bed and forget about everything that happened to […]
The danger of “I know it when I see it” identification
I have written here before about the danger of the “I know it when I see it” approach and even in combination with screening tests such as the NIK Public Safety tests. Roadside screening tests such as the NIK Public Safety Reagent Based Tests Can Provide False Positives. Here is another unfortunate example of bad […]
Forensic Science Blogs that I watch
If you don’t have Google Reader with subscriptions set up, then I think you are either drowning in information or don’t have an effective and efficient way of managing your time to make sure that you don’t miss out on information. I personally monitor over 200 blogs each and every day in real time using […]
Another crime laboratory in danger: US Army
Some folks seem to think that laboratory errors are confined to local laboratories and rouge out-of-control isolated agents who are either sloppy or up to no good. Intuitively, we know this is not true. Laboratories are run by humans. Humans make mistakes. Some humans deliberately lie to get what they want and to keep themselves […]
Roadside screening tests such as the NIK Public Safety Reagent Based Tests Can Provide False Positives
Screening tests can lead to false arrests. The characteristics of a screening test are that they are easy to use with little to no training. They are used at a point of first contact meaning typically at roadside. In science, it seems as if there is the continual struggle between fast, cheap and good. It […]
Is it legitimate for a crime laboratory to use ‘historical data’ to prove its test results are valid?
I am lucky to get questions from colleagues. I am honored by it, and I thank them for the opportunity to answer their questions. From time to time I am going to feature questions that I get from them if they provide for teachable concepts. This question from a colleague provides for just such an […]
The discretion exercised every day and with every test in forensic science
Unless you are a scientist, you probably do not realize that analysts in forensic science exercise a massive amount of discretion with the reporting of data. In a thought provoking article that appeared on www.SeparationsNow.com and in their “Lab Infomatics” section reads: It’s the analytical scientist’s perennial dilemma: where to strike the balance between convenience […]
Forensic Science Ombudsman
I am in Chicago learning at the footsteps at the true master of modern day cross examination Terence MacCarthy. If you go into a courtroom to argue your case, his book is a must. If you can catch him at a presentation it is even better. Here in Chicago, I am lucky to be in […]
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