Eyewitness identification, though not consistently reliable, has been used as one of main means of prosecuting evidence against the accused for centuries. Today, law enforcement and criminal prosecutors still rely on eyewitness testimony in an estimated eighty thousand cases annually. In many instances, cases tried based on eyewitness identification alone are inherently flawed and can lead to the conviction of innocent individuals. Therefore, with so much riding on having a correct eyewitness statement, criminal law has very specific practices concerning eyewitness testimony, suspect lineups, and suspect show-ups.
Litanies of scientific experiments have been conducted assessing the accuracy of eyewitness accounts, and the psychological and cognitive processes that may result in a right or wrong eyewitness testimony. A wide variety of factors may influence an eyewitness testimony. As a rule, the most adamant eyewitness is no more reliable than the eyewitness that has some degree of doubt. They believe what their mind can recall, which can easily be flawed due to a number of known factors, including:
Proving or disproving the efficacy of a given eyewitness rests on influencing the jury members to believe or disbelieve the testimony of a witness. Again, forensic evidence can corroborate an eyewitness account or further cast doubt on the accuracy. Each case is different, and defendants may actively use an expert witness familiar with cognitive psychology to educate jury members on the traits of accurate or inaccurate eyewitness accounts.
Law enforcement, detectives, and prosecutors regularly rely on eyewitness testimony to locate suspects or other evidence when solving a given crime. Many times, law enforcement seeks forensic evidence results to corroborate their already existing arrests and investigation into a crime. There are a number of commonly used methods that law enforcement will employ to identify suspects, which gives them enough probable cause to detain these individuals for further questioning.
During an investigation, law enforcement may use a lineup of a suspect and four to five other individuals. In this scenario, a witness will be asked to identify any suspects of the crime from the given lineup. Typically, law enforcement can force arrested individuals to participate in a lineup. However, the effectiveness of the results of a lineup is often disputed by defense attorneys on numerous grounds, the most common being the lineup was “unfair or biased”. Numerous factors can influence the results of a lineup, including law enforcement guidance, conversations, and an instruction to the eyewitness, as well as other factors about the credibility of the eyewitness themselves.
Showups occur when a law enforcement official allows an eyewitness to view a suspect one on one. Typically, these eyewitness identifications occur immediately following a crime and arrest, when a suspected is apprehended in the area. Often, a showup happens while a suspect is being detained, but has not been formally charged with a crime. However, misidentification is also possible here as well, and defense attorneys can challenge the legality of this identification in a number of ways, such as the fact that an individual is probably in handcuffs in the back of a police car and essentially looks like a “suspect”.
More commonly today, law enforcement will use a photo lineup of potential suspects to gain enough probable cause to issue an arrest. Essentially, eyewitnesses are shown what is known as a “six pack”, which includes mug shots of the potential suspect and five other individuals of similar race, build, complexion, and other factors. If a suspect identifies a suspect, law enforcement must document this identification and the photos used in the “six pack”. The legality of the “six pack” can be challenged because the photos shown are not significantly similar enough, or some form of aberration differentiates a suspect from the others persons in the photo lineup.
Defense attorneys can motion to suppress identifications during pretrial proceedings on the grounds that the eyewitness identification was unfair, coerced, or was unnecessarily suggestive of a defendant’s guilt that misidentification was unnecessarily possible. To suppress identifications, the burden of proof is on defendants to prove the enhanced possibility of misidentification. However, law enforcement officers are typically very aware of the procedures to properly prepare an eyewitness identification, and the defendant must work proactively to prove that some violation or unfair statement, action, or incident occurred leading to a heightened possibility of an irreparable misidentification.