Each year in the United States, about a million people are pulled over on suspicion of drunk driving. In virtually all of those cases, the driver is asked to blow into a breathalyzer-style machine that estimates their blood-alcohol content. If it's above a certain level, typically 0.08%, the driver is arrested and brought to the precinct for additional testing.
In 2009, the National Academy of Sciences (NAS) issued a blockbuster report challenging the scientific underpinnings of many fields of forensic evidence. The report found that such evidence is rarely supported by rigorous study. Moreover, the analyses are often performed unscientifically, and analysts often overstate the scientific rigor of their evidence during testimony.
In 2009, the National Academy of Sciences issued a blockbuster report on the state of the science in forensic investigation. That report concluded that, "with the exception of nuclear DNA analysis ... no forensic method has been rigorously shown to have the capacity to consistently, and with a high degree of certainty, demonstrate a connection between evidence and a specific individual or source."
A jailhouse informant is rarely someone who just wants to help. Jails and prisons have a strong anti-snitching culture, so passing along information to prosecutors is a choice that could get you in serious trouble. People don't inform on other prisoners to be solid citizens; they do it to get a break on their sentences.
Polygraph tests, often called "lie-detector tests," are not admissible as evidence in the courts. This is because they have never been shown to produce reliable proof of whether the subject is lying.
We've discussed on this blog how genealogy databases like GEDmatch warehouse the DNA results of huge numbers of people who have taken part in genetic testing for genealogy purposes.
Forensic In February 2009, the National Academy of Sciences (NAS) released a ground-breaking report called "Strengthening Forensic Science in the United States, A Path Forward." Researchers at NAS had looked at the state of forensic science in the U.S. and found serious problems.
In 1963, the U.S. Supreme Court held in Brady v. Maryland that police and prosecutors are legally bound to turn over so-called "exculpatory" evidence to the defense before trial. Exculpatory evidence is most anything favorable to the defense. It can be evidence that the defendant is innocent, that someone else could be guilty, or that there were mitigating circumstances. Or, it can cast doubt on the reliability of prosecution witnesses.
Matthew C. was charged with possessing 92 grams of heroin after a baggie full of white powder was discovered in his van. The powder allegedly tested positive for heroin in a field test. In reality, it was laundry detergent.
If you've been reading our blog, you know that many common forensic evidence techniques have been called into serious question by scientists. Yet police, prosecutors and judges continue to use or allow these techniques to be used. Sometimes, it seems as if they are used simply because they have been in use for so long. That isn't sound policy.