Imagine this: You're arrested for some sort of crime, whether it's drunk driving, drug possession, assault or something else. You're absolutely sure that you're innocent -- but the police tell you that the evidence says you're lying. "Forensics," they may say, "never lie."
For many criminal defendants, this scenario is a reality that plays out more or less exactly as described. Many -- convinced that they can't prove their innocence when the forensic evidence is against them -- give up and take a guilty plea almost immediately.
That's a big mistake, however, because there's a growing understanding in the scientific community that much of what was once considered "iron-clad" forensic evidence is nothing more than supposition and junk science. Some of the most well-known types of forensic evidence used in court is now being questioned -- and rightly so!
After a careful review, the National Academy of Sciences declared that many kinds of "forensic evidence" that is commonly presented "to a reasonable degree of certainty" against defendants in criminal cases isn't really based on any science at all -- and definitely isn't certain. Many so-called experts offer testimony that is, in reality, little more than their opinion -- something far removed from the cold facts they claim the evidence presents.
Take, for example, bite mark evidence. Experts who specialize in bite mark identification claim that there is a one in 10 quadrillion chance of misidentification -- yet actual experiments show that even experienced investigators are wrong about one out of every six times. The Federal Bureau of Investigation (FBI) had to shut down its own lab after discovering that agency experts made mistakes in ballistic identification one out of every 10 times. Even fingerprint analysis (which is one of the oldest forms of forensics) is questionable. Close evaluations revealed that FBI examiners -- arguably the "best of the best" in the business -- made errors in one out of every 24 cases.
All of this should tell defendants one thing: There's often room for doubt where forensics are concerned, no matter what the police and prosecutors may say. If you've been charged with a crime and the forensic evidence is stacked against you, don't assume your case is hopeless. A defense attorney may have a different view.