The Dangerous Unreliability of Eyewitnesses

Summary

The video script discusses the crucial role of eyewitness testimony in wrongful convictions and the scientific research behind improving identification accuracy. It highlights reforms in police procedures, such as warning witnesses that a suspect may not be present in lineups, and ensuring the administrator is unaware of the suspect. The script also critiques forensic techniques like fingerprint and bullet analysis, emphasizing the lack of scientific validation compared to DNA testing. The National Academy of Science urges a reevaluation of traditional forensic methods to ensure accuracy in criminal investigations.

Takeaways

• 🧠 Eyewitness testimony is the leading cause of wrongful convictions, despite extensive psychological research on its unreliability.
• 🔬 Over 30 years of research by experimental psychologists have explored how different techniques for photo arrays and lineups impact the accuracy of identifications.
• 📉 Simply warning a witness that the perpetrator may not be in a lineup can significantly reduce incorrect identifications without affecting accurate ones.
• 🔍 Double-blind procedures, where the administrator doesn't know the suspect, prevent bias and the influence of confirming feedback on witnesses.
• 📈 Confirming feedback, like praising a witness for their choice, can falsely increase their certainty and belief in their identification accuracy.
• ⚖️ Legal tests used to determine the reliability of witness identifications, such as certainty and attention, are misaligned with scientific evidence.
• 📚 A National Academy of Science report on forensic science stated that DNA testing is the only fully validated forensic method.
• 🧩 Pattern evidence such as fingerprints, tire tracks, and bullet striations lacks sufficient validation and statistical backing for reliability in court.
• ❌ Claims that a bullet or fingerprint uniquely matches a suspect’s gun or print to the exclusion of all others are scientifically unfounded.
• 🔄 The scientific community is urged to re-evaluate and research forensic pattern evidence to establish a more robust and reliable basis for use in court.

Q & A

What is considered the single greatest cause of wrongful convictions?

Eyewitness testimony is considered the single greatest cause of the conviction of innocent people.

What has experimental psychology research shown about eyewitness identification?

Research has shown that certain techniques, such as how photo arrays and lineups are conducted, can either improve the accuracy of identifications or lead to errors. The research highlights ways to enhance reliable identifications and reduce mistakes.

What is the significance of warning a witness that the perpetrator may or may not be in a lineup or photo array?

Giving this warning significantly reduces incorrect identifications without lowering the number of correct identifications. It helps prevent witnesses from guessing.

Why should the person administering a lineup or photo array be 'double-blinded'?

The administrator should not know who the suspect is to avoid influencing the witness, either intentionally or unintentionally. This prevents bias or feedback that could falsely inflate the witness’s certainty.

What is the effect of giving confirming feedback to a witness after identification?

Confirming feedback, such as telling a witness they made a correct identification, can falsely inflate their confidence in their choice and their belief that they had a good opportunity to observe the crime.

How does confirming feedback affect legal tests for eyewitness reliability?

Confirming feedback can distort factors like certainty, opportunity to observe, and attention, which are traditionally used by courts to evaluate eyewitness reliability, making these legal tests misaligned with scientific evidence.

What does the National Academy of Science report say about forensic sciences?

The report states that DNA testing is the only fully validated forensic discipline. Other pattern-based evidence, like fingerprints and bullet striations, lacks sufficient scientific validation.

What are the concerns with pattern-based forensic evidence like fingerprints and bullet striations?

Pattern-based evidence, such as fingerprints or bullet striations, often lacks a proper scientific foundation, including databases and statistical measures, to support claims of uniqueness or identification.

Why is DNA testing considered more reliable than other forensic disciplines?

DNA testing provides a statistical basis, offering frequency estimates for specific DNA profiles in different populations, unlike other forensic methods that often rely on subjective interpretations without statistical backing.

What did the National Academy of Science recommend for forensic disciplines besides DNA testing?

The Academy recommended that forensic disciplines like fingerprint analysis and bullet striation matching undergo more basic research to establish scientific validity and develop objective metrics for their findings.