Report urges caution in use of Pennsylvania eyewitness testimony

Research shows that memory is dynamic and vulnerable to distortion. However, new criminal law procedures could reduce the risk of eyewitness errors.

Eyewitness testimony is often given credence in Philadelphia criminal cases, since many people believe that an eyewitness's memories are akin to video recordings. Still, research increasingly shows that this isn't the case; eyewitness errors are a common factor in wrongful convictions. A recent report highlights this risk, along with steps that authorities should take to mitigate it any time that someone is charged with a crime based on eyewitness evidence.

Constantly changing memories

According to The Washington Post, the National Academy of Sciences report explains that memory is not static. The brain has the ability to alter memories as they are created, stored or recalled. This essentially means that people are regularly losing, filling in and even fabricating aspects of their memories, often without even realizing they have done so.

Troublingly, even if memory were perfect, factors at the scene of an alleged crime could still undermine the accuracy of an observer's memory. The following variables can result in a memory that is flawed from the beginning:

  • Poor lighting, large viewing distance and other unfavorable viewing factors
  • The eyewitness's emotions at the time of the incident
  • The alleged offender's threats, intimidating tactics or use of a deadly weapon
  • The eyewitness's own biases

It's not surprising that the Innocence Project reports that eyewitness errors have been contributing factors in 73 percent of wrongful convictions later overturned through DNA testing. Human memory is simply not always reliable. However, the use of certain protocols during the criminal justice process could help prevent some unnecessary eyewitness mistakes.

Minimizing the risk of errors

The NAS report recommends that law enforcement authorities make several changes to avoid inadvertently biasing eyewitnesses or contaminating their memories. Authorities should conduct blind lineups, in which the supervising police officer is unaware of the suspect's identity, and the lineup procedures should be recorded. Standardized instructions should advise eyewitnesses that the suspect might not be present and that failing to identify anyone is acceptable.

Additionally, the report suggests that each eyewitness who makes an identification should give a statement describing his or her confidence in it immediately afterward. This prevents shaky identifications from being presented as certain identifications later. It also helps address the issue of eyewitnesses receiving feedback and becoming overly confident in their identifications by the time they testify in trial.

Questioning eyewitness credibility

Although Pennsylvania has not uniformly implemented these changes, the state has taken one important step toward preventing eyewitness errors. In 2014, the state Supreme Court ruled that experts in the science of eyewitness testimony should no longer be banned from testifying in criminal trials, according to The Pittsburgh Tribune-Review.

Such testimony was banned in the past because jurors were considered capable of personally judging the credibility of an eyewitness. However, experts worried that jurors might not reach the right decision without understanding how human memory works and how various factors can distort eyewitness impressions. This change is expected to particularly impact alleged cases of robbery and sexual assault, but it may affect many other cases as well.

Anyone who is facing serious charges bolstered by eyewitness testimony should consider meeting with a criminal defense attorney who understands the potential problems with this evidence. Bringing the limitations of eyewitness testimony to light may make a significant difference in the final outcome of the case.

Keywords: eyewitness, testimony, wrongful, conviction