Science is a fundamental aspect of modern crime prosecution. Most courtroom science is related to evidence found at crime scenes and analysis of fingerprints, footprints, weapons, blood, hair and other similar items. These pieces of evidence are often used to prove in the eyes of the state that an individual committed the crime.
Experts in forensic science are called to testify in court regarding forensic evidence in particular cases. However, many unreliable expert forensic science testimonies involve junk science. Junk science is a term used for untested or unproven theories displayed as scientific fact. These experts often testify to methods of evidence analysis that are not scientifically proven. They may string together pieces of evidence, linking a person to a crime without proper analysis. Unreliable forensic science testimony is one of the top causes of wrongful convictions.
How do unreliable testimonies happen?
Experts are often brought to court to testify who have dramatically exaggerated their level of knowledge in the field. They usually fail to discuss the likelihood of error in their methods of forensic analysis. Some forensic experts are willing to shape information to support a conviction due to a police prosecution bias.
Fortunately, the court system is taking steps towards recognizing flawed forensic science testimony used to convict so many defendants over the past few decades. What used to be considered as hard evidence is now considered unreliable due to newer research. For example, forensic experts once relied on techniques such as comparative bullet lead analysis, handwriting analysis, and hair microscopy that are no longer accepted in some courts. These methods were utilized in courtrooms by highly credentialed experts at one time.
Juries and the “Reverse CSI-Effect”
It appears that jurors are strongly convinced by forensic experts in court. They are impacted by what is called the “CSI-Effect”- the notion that jurors cannot differentiate between the exaggerated portrayals of the capabilities of forensic science on TV between the true capabilities of forensic science. They assume that hard scientific evidence must be presented in order to convict a person, leading to acquittals.
However, it is the “Reverse CSI-Effect” that may be a greater threat to the justice system and people caught in it. Many prosecutors believe that modern jury members are swayed by the “Reverse CSI-Effect” before ever being presented with forensic testimony on a case. They put too much weight on forensic science, taking any forensic evidence presented at trial as the final word in the case.
There have been a number of cases where forensic testimony was presented that swayed the jury to prosecute an individual wrongfully. Years or even decades later, further research finds that the evidence was faulty. One study shows that 63 percent of wrongful convictions included a forensic science error. However, people who believe they were wrongfully convicted due to junk science can seek post-conviction relief with the help of an attorney.