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Forensic Science

Airplanes And Alphabet Soup

We all have some modest expectations when taking a plane ride. Personally, I expect that the plane will stay in the air as long as it is supposed to. I would expect a pilot that actually knows how to competently fly the plane. And most importantly, I expect to walk away from the landing. These things do not seem too… keep reading »

Beware of False Scales

It’s an old warning, but it still holds true – beware of false scales. Throughout history the admonition against using a numerical value to mislead others has taken many forms: Proverbs 11:1 tells us “[t]he Lord detests the use of dishonest scales, but he delights in accurate weights”; Leviticus 19:35 cautions “‘[d]o not use dishonest standards when measuring length, weight… keep reading »

Voting in the dark

Transparency enables us to know what we are voting for.  However: 
“One person one vote” — not true…if you don’t know what your voting for; “You vote your conscience” — not true…if you don’t know what your voting for; “You verdict is justice” — not true…if you don’t know what your voting for.
We have important decisions to make.  All
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The Scottsdale Crime Lab, Isaac Asimov & The Arizona Supreme Court

The most exciting phrase to hear in science, the one that heralds new discoveries, is not “Eureka” but “That’s funny…” ~Isaac Asimov (1920–1992) Over 3 years ago, myself and few other attorneys stumbled upon something that we could not explain. It was a printout of from a machine called a gas chromatograph. Gas chromatograph’s are commonly used in DUI cases… keep reading »


In Daubert jurisdictions, like Arizona, a judge is supposed to be a gatekeeper preventing unreliable scientific evidence from reaching a jury.  A primary reason for making judges perform this task is the danger that things that sound like science can be misleading.  At times, even cross-examination under the limitations of a jury trial cannot always debunk such evidence.  … keep reading »

Fool’s Gold

Fool’s gold is a golden colored mineral that is often mistaken for real gold. The term is also used to describe anything, which a person believes to be valuable, but in reality is not. The reference to gold, or “the gold standard” is commonly used when describing gas chromatography. Unlike pyrite (the mineral which the term is named) there is… keep reading »

A reliable ruler

A ruler is an instrument used to measure.  If you want to know the length of an object, then holding a ruler next to an object is a common technique.  At the end of this measurement process, you will produce a number.  If “the number” is not that important, then an eyeball “guesstimate” will be sufficient.  If, however, “the number”… keep reading »

Two thing at one time is not proof of neither

Every so often the case arises where a blood test result falls within a margin of error.  For example, assume the law provides that a person is guilty of DUI when their blood alcohol concentration is .08 or greater.  Also assume that the prosecution tests a person’s blood and the result is .085.  This result is within the test’s margin… keep reading »

Shakespeare, A God Complex and Zero Error Rates

The basic plot of Hamlet is: Hamlet’s uncle Claudius kills his dad (who is king). Uncle Claudius, then marries Hamlet’s mom Gertrude, and becomes the new king. Hamlet sees his dad’s ghost, who tells Hamlet, Claudius killed him. Hamlet seeks revenge on Claudius. In the end – everyone dies.

Hamlet’s God Complex

Hamlet sees the world through a fog of… keep reading »

Real blood testing

A label does not create reality, nor reliability. Real Blood testing requires a methodology which includes several techniques and methods that must be done correctly though out the entire process. This process includes both human dependent and machine dependent steps. As the United States Supreme Court in Bullcoming v. New Mexico held: Although the State presented testimony that obtaining an keep reading »