Forensic Tools: What’s Reliable and What’s Not-So-Scientific
For years, American TV shows have featured crime scene investigators using forensic evidence to solve grim murders. Often, however, these fictional CSIs present unrealistic portrayals of the capabilities of forensic science.
The reality is that not all forensic evidence is backed up by rigorous scientific research – meaning it doesn’t always point to the person who “did it.” A landmark 2009 study by the National Academy of Sciences (NAS) highlighted the tools that work – and those that fall short. Here’s a sampling of the basics:
DNA Analysis is the Gold Standard
In 1984, a British geneticist named Alec Jeffreys stumbled upon one of our most important forensic tools: DNA fingerprinting. Since his “eureka moment,” the scientific technique has been used successfully to identify perpetrators of a crime, clarify paternity and exonerate people wrongly convicted.
Today, the testing and analysis of DNA is considered the most reliable of all of the forensic tools. Unlike many of the others gathered to meet the needs of law enforcement, it faced rigorous scientific experimentation and validation prior to its use in forensic science.
“Among the biggest problems that we uncovered in the report is the absence of the application of scientific methodology to determine whether or not the discipline was valid and reliable as was done with DNA,” says Harry T. Edwards, a U.S. federal judge and part of the NAS committee that produced that 2009 report. “DNA is really the only discipline among the forensic disciplines that consistently produces results that you can rely on with a fair level of confidence, when you’re seeking to determine whether or not a piece of evidence is connected with a particular source.” …