When police officers in Texas and around the country arrive at a crime scene, they usually begin their inquiries by taking statements from any individuals who saw the events take place. As the investigation unfolds, eyewitnesses may be asked to help police identify a suspect by looking at mugshot photos or attending lineups. Police officers, prosecutors and juries place a lot of trust in eyewitness testimony, but studies suggest that this faith is often misplaced. Recollections of stressful events that took place in a matter of seconds can be unreliable, and this is especially true when witnesses and the people they identify are not of the same race.
Most people consider it their civic duty to help the police solve crimes, which can make them overly eager to help and undermine their impartiality. The pressure on witnesses to do their duty can be particularly strong when police imply that a case hinges on their recollections, and it can lead to misidentifications and innocent individuals being convicted and incarcerated. Between its founding and January 2020, the Innocence Project used DNA evidence to successfully overturn 367 wrongful convictions. Eyewitness testimony was a factor in 260 of these cases.
Researchers have found that memories tend to fade over time and become contaminated, and they have also discovered that even minor changes in the words used by police officers can influence eyewitness accounts. Co-witness conformity, which is also known as the bandwagon effect, could also make first-hand accounts less reliable. This can happen when witnesses discuss the events with each other before talking to the police.
Advocating on behalf of the accused
Experienced criminal law attorneys may study case files very closely when prosecutors base their cases on eyewitness testimony. Attorneys could scrutinize the words police officers used when they questioned witnesses and the procedures that were followed during lineups. During trials, attorneys may call on experts to cite studies about misidentification and bias. They could argue that establishing proof beyond reasonable doubt based on eyewitness testimony alone is not possible.