Through the exonerations of innocent people, records show that misleading experts and bad forensic evidence are to blame for false convictions. There are high-profile cases where experts lead the jury astray.
Forensic evidence and expert witness issues
Bad science underlying forensic evidence can complicate a criminal defense strategy. An example is convicting someone of assault from a bite mark. Some people think that every bite mark fits only one mouth, but bite marks can’t uniquely identify a person.
Some situations use strong science, but the expert witness misrepresents the facts. The misuse of research isn’t usually on purpose; the expert can have inattentional blindness.
The science of intentional blindness
Inattentional blindness is when people get confused in a complex situation while focusing on something. A person focusing on one thing can fail to see the unexpected. A study on inattentional blindness had students watch two basketball players. The class was counting the passes of a player to focus. Then, a woman with an umbrella walked onto the court. The students who were counting the passes missed the woman’s appearance. There are many documented studies on inattentional blindness.
Misrepresentation of a real effect
Expert witnesses can misrepresent the real effect of inattentional blindness and hurt criminal defense. One expert who trains police uses inattentional blindness as a police shooting defense, saying the police might miss crucial details, such as not seeing a weapon or the victim being a child. However, people who suffer from inattentional blindness miss details outside of the situation, not features of their focus.
Evaluating the misrepresented claims
There isn’t enough scientific data to justify intentional blindness causing police shootings or memory lapses. In one study, people focused on a point and remembered more details, which is the opposite of the basketball study.
Expert witness testimonies can make or break a case, but an expert witness can skew evidence with misrepresentation. Outdated methods can lead to an innocent person’s conviction. There are aspects of inattentional blindness that can help in situations, but there isn’t science on using it as the only defense.