After nearly a week in Arlington, I had the chance to learn what a lab should do, and how to utilize those skills in the trial.  Serious Science: Drug Specimen Analysis gave me the tools to show where the government technicians make their mistakes, and why it makes a difference.
           
One area which leads to the most mistakes is sample preparation.  When the technician removes the sample to prepare it to go into the machine, there are numerous steps that must be done correctly.  If the steps are not performed correctly, then the results are not reliable.  And when the results are not reliable, they should be rejected.
           
One crucial step is the pipetting of the samples.  A pipette is like a turkey baster which is used to draw fluids out of the containers submitted to the lab and transferred them to vials for testing.  Put the wrong fluid in the container, or the wrong amount, and the test could be incorrectly identified or improperly elevated.
           
How you pipette does matter.  If you do it wrong, your results are wrong.  Not defendable, but just plain garbage.  So, next time you have a case where pipetting occurs, log into the library and see whether they did it right.

We know government labs create a conveyor belt mentality in their testing process.  They force the techs to push through as many samples as they can, and they fail to properly train these techs on what to look for, and how to ensure there are no problems in the run.  When a tech sees a problem, they do not see a problem, because they have not been trained to identify it as a problem.  The same can be said for their understanding of Method Validation and Proficiency testing.
           
In Analysis of the Relationships Between Proficiency Testing, Validation of Methods and Estimation of Measurement Uncertainty, by Albano and Caten, Accred Qual Assur (2016) 21:161-166, they point out the necessity of these processes to ensure quality results.  Method validation is important, and is "the confirmation, through objective evidence, that the specific measurement requirements are met for an intended use."  It looks for where lab errors can occur.  And "therefore, it is important to validate every stage of the test or calibration in the laboratory environment."  So, did they properly perform the method validation, and have they checked it with their Proficiency testing.
           
Forensic crime labs rely upon institutional knowledge, and work performed years ago if ever, to show they have performed method validation.  They then attempt to use what they call proficiency testing to justify their results.  However, if they have not properly performed, or can prove, the existence of the method validation, they cannot prove the reliability of the results.  Another jewel in the forensic library.  

In just about every DUID marijuana case the officer states he saw a green tongue. That the green tongue is evidence of recent marijuana use.  The green tongue is then used to justify an arrest and a DRE screen.  We know this is BS, and what can we do to challenge it.  Well, the virtual library, thanks to George Bianci, has a number of motions and articles related to the green tongue fallacy.
           
There is no scientific support for this claim.  There is nothing to suggest that recent marijuana use and a green tongue are related. In fact, it seem counter-intuitive as the plant has been dried and burned before it is consumed.

So the next time a law enforcement officer tries to bamboozle the court with the green tongue argument, counter with the unreliable and unscientifically proven argument. Find the Motion in the Library and convince your judge that this unreliable evidence should not be admissible. 

As a DUI Defense Attorney, we are looking for any manner to challenge the breath test.  One is the presence of RFI.  However, the government is constantly telling us it's not a problem.  It doesn't affect the test.  They just trying to cloud the issues. But the government knows better, and it is a problem.

While a bit dated, the NHTSA's Limited Electromagnetic Interference Testing of Evidential Breath Testers points out this concern.

The report stated that states should subject to their instruments to field testing to determine susceptibility. They recognize that the evidential breath testing devices may be adversely effected by RFI.  That the RFI has a potential for inaccurate results. 

How has this changed over the years, it's still present. The manufactures have improved the quality of the shielding, but it can still impact the result.  I have observed a cell phone ringing during a test that increased the result at a training. It does happen.

Today with digital phones, mini-pocket computers, radio's on a digital wave length, not to mention all the other electronic data around the breath machine, we just don't know how bad it is.  And we just don't know cannot be the mantra the government relies upon.