I know what I saw! When an eyewitness to a crime gives evidence in court, that testimony often overwhelms evidence to the contrary. Faced with conflicting or ambiguous testimony, jurors tend to put their faith in people who saw an event with their own eyes. However, there is now compelling evidence that this faith in eyewitnesses is often misplaced.

For more than four decades, Elizabeth Loftus (1993, 2013; Loftus & Pickrell, 1995) has been the most influential researcher into eyewitness memory. In a classic study, Loftus and Palmer (1974) showed experimental participants a film depicting a traffic accident. Some of the participants were asked, “About how fast were the cars going when they hit each other?” Other participants were asked the same question, but with the words smashed into, collided with, bumped into, or contacted in place of hit. The researchers discovered that people’s reports of the cars’ speeds depended on which word was inserted in the question. Those asked about cars that “smashed into” each other reported that the cars were going faster than those who were asked about cars that “contacted” each other. In another experiment, the participants were also shown a film of a collision and then were asked either “How fast were the cars going when they hit each other?” or “How fast were the cars going when they smashed into each other?” One week later, they were asked some additional questions about the accident that they had seen on film the week before. One of the questions was “Did you see any broken glass?” More of the participants who had been asked about cars that had “smashed into” each other reported that they had seen broken glass than did participants who had been asked the speed of cars that “hit” each other. These findings illustrate how police, lawyers, and other investigators may, often unconsciously, sway witnesses and influence subsequent eyewitness accounts. On the basis of experiments like these, Loftus and Palmer concluded that eyewitness testimony is unreliable.

So why do eyewitnesses make mistakes? Before you watch the next video, ask yourself how your own memories have changed or became distorted over time. Now, consider the consequences of these changes as it relates to eyewitness testimony or even our closest relationships.

Whatever the reason for eyewitness errors, there is good evidence that such mistakes can send thousands of innocent people to jail each year in the United States (Pezdek, 2007). For example, based almost entirely on the eyewitness identification testimony of a single individual, Steven Avery was convicted of brutally attacking, raping, and nearly killing a woman in 1985 and was sentenced to 32 years in prison. Although Avery offered alibis from 14 witnesses and documentation showing he wasn’t at the scene of the crime, it took repeated legal challenges and new advances in DNA testing for him to overcome the conviction. Finally, on September 11, 2003, Mr. Avery was exonerated of all charges and released from prison. Increasingly, courts are recognizing the limits of eyewitness testimony and are taking steps to teach jurors how to properly evaluate it (Martire & Kemp, 2011).