Weapon focus is a factor affecting the reliability of eyewitness testimony. Weapon focus signifies a witness to a crime diverting his or her attention to the weapon the perpetrator is holding, thus leaving less attention for other details in the scene and leading to memory impairments later for those other details. Elizabeth Loftus, Yuille and Burns, have all been associated with studies showing the existence of a weapon focus effect. According to a 2001 survey of eyewitness experts, 87% found the effect sufficiently reliable to form the basis of expert testimony in criminal trials.
In the field of forensic psychology, researchers have validated the weapon focus effect and shown that a witness will remember less about a crime, or the perpetrator of a crime, when a weapon is present, as opposed to if the weapon is not present at an identical crime. As for the reason the phenomenon occurs, the two leading explanations attribute it to the cognitive arousal of the victim, or to the overall unusualness of the situation.
In one of the earliest known investigations of weapon focus, Johnson and Scott (1976) had two groups of participants come into what they thought was a laboratory study of human memory. In actuality they were to take part in a simulated interaction intended to determine whether the presence of a weapon would influence eyewitness memory for an event. Participants in the control condition sat in a waiting room where they overheard a conversation between two people following which a man exited with greasy hands and a grease pen. In the weapon condition participants sat in the same waiting room, but instead they heard a violent argument - including furniture being thrown around - following which a man came out holding a blood-stained knife. During a photo line-up, the control participants were more likely to accurately identify the man they saw in the waiting room relative to participants in the weapon condition (49% versus 33% correct identifications).
The study conducted by Johnson and Scott (1976) represents one of the few simulation studies available, likely due to the ethical issues surrounding the exposure of research participants to a putatively threatening scenario. For this reason much of the research conducted on the weapon focus effect has made use of videos or slide shows. In one of the first such experiments, Loftus, Loftus and Messo (1987) had participants watch a video in which a young man approached the counter of a fast food restaurant, presented an object to the cashier, accepted money and left. In the control condition the man presented a cheque to the cashier whereas in the weapon condition the man presented a gun. Specialized equipment tracked the participant's gaze as they viewed the video to determine with what frequency (and for how long) they fixated upon the item of interest (the cheque or the gun). Relative to the control condition, participants in the weapon condition looked at the item the man was holding more frequently and for greater duration. Further, when tested for the details of the event, performance was better for the control condition relative to the weapon condition - with the exception that participants in the weapon condition were more likely to recall what object the man was holding (a gun).
Since the initial research conducted by Johnson and Scott (1976) and Loftus et al. (1987) others have demonstrated a similar effect using not weapons but unusual objects. For example, Pickel (1998) demonstrated an effect comparable to weapon focus using a video in which a man approached a cashier and presented a whole raw chicken or miniature Pillsbury Dough Boy instead of an expected item such as a wallet. From her finding, Pickel (1998) argued that the weapon focus arose from the unusual nature of the object in the relation to the context in which it was presented. The relative contributions of arousal and unusualness remains one of the primary theoretical issues in this literature, with some authors arguing for a contribution of both.
Another significant challenge to the weapon focus effect has been its ecological validity. Specifically, many theorists have argued that the effect is limited to the laboratory. These claims have been supported by the relative absence of applied evidence supporting the effect. Several reports have been published looking for evidence of a weapon focus effect using records of actual criminal events. According to the laboratory findings summarized above, the prediction had been that eyewitness memory would be worse for weapon crimes compared to non-weapon crimes. Many of the primary studies failed to support this prediction. Even so, a recent meta-analysis conducted by Fawcett et al. (2013) has demonstrated that when the data for all of the applied studies are combined, there is a small but reliable effect suggesting that weapon presence impairs actual eyewitness memory. This finding supports the laboratory studies conducted on this topic.
Why Weapon Focus Occurs
Why weapon focus occurs has been described a couple different ways. The first is the “automatic capture” explanation. This suggests that the attention paid to a weapon is automatic and unintentional. Studies have been performed that show that even if a subject is asked to ignore specific stimuli they are unable to thus eliciting an automatic response. However, other research shows that attention focus is not automatic and can be directed on command, especially if attention is already focused somewhere specific. If attention is already focused away from a certain stimulus, then automatic capture is avoidable.
Pickel, Ross, and Truelove (2006) decided to take a more in depth look at these ideas and apply them specifically to weapon focus. If weapon focus is an automatic process, then the capture of attention may be out of an eyewitness’ control. However, if there is no automatic capture of the witness’ attention, then weapon focus effect may be able to be overcome. Specific training can be developed to teach a person who may be at risk of an armed robbery, such as a bank teller or cashier, to perform an identification that is comparable to if there was no weapon present. The data indicate that weapons do not capture attention automatically and involuntarily. If a witness was given a lecture about weapon focus and the problems that can arise in memory formation in an incident when a weapon is present at the scene, they can more accurately identify a perpetrator of a crime. This shows that with proper training weapon focus effect can be overcome and an eyewitness’ testimony becomes more accurate. These findings, however, are theoretical and need to be replicated in real world situations to really assess the usefulness of them. They show great promise that weapon focus effect and be counteracted by education on the topic, but they will remain theoretical until further research and implementation of the idea can be conducted.
Reducing Weapon Focus
One method that has become more and more prevalent to reduce negative consequences that can stem from errors in eyewitness testimony, including errors that can arise from weapon focus effect, is expert witness testimonies by research psychologists about eyewitness testimony. This is an educational session, which a judge has to allow, given by a forensic psychologist to a jury as part of the trial. This form of expert testimony has been called social framework testimony, defined by Cronin  as “expert testimony that presents conclusions based on social science research to assist the court in making a decision.” The expert testimony would provide the jury with a context for evaluating eyewitness testimonies and the jury is meant to factor that into its decision making process. These educational sessions in the courtroom will help make the presentation of eyewitness testimony as rigorous as process and put as much scrutiny on the social evidence as what is put on physical, scientific evidence. Eyewitness testimony is very often wrong, and the scrutiny put on it greatly reduces the number of false convictions.
The major problem with this strategy is that many judges do not allow this expert testimony in their courts. Their reasoning is usually that they think what the social framework testimony will present is common knowledge. However, the data overwhelmingly shows that the typical jury member does not know most of the information presented by the expert. The fallibility of eyewitness testimony is not common knowledge and eyewitness psychology can offer valid and constructive information to juries. Even with this knowledge, jury decisions cannot perfectly serve justice without exceptions but perfection in the legal system is an unattainable goal. However, any information the can be presented about the shortcomings of eyewitness testimony can better serve justice in the long run.
There can be some ethical concerns to these expert witnesses. There are arguments that suggest that these social framework testimonies serve to discredit the eyewitnesses and put the victims and bystanders on trial. This is not the purpose of the experts though. These testimonies are merely attempting to educate jury members of problems that can arise from eyewitnesses. There can also be issues raised about the credibility of the expert testimonies. The screening process of the experts is not very stringent and the criteria of an expert witness are not laid out in black in white. This can lead to a battle of the experts between prosecution and defense. Any testimony the prosecution of defense deems relevant to contradict the opposing side, and if the judge allows it, an expert can be called and a battle of the experts can ensue. This takes away from the central point of a trial and can overwhelm the jury. This can also perpetuate the stereotype of a ruthless lawyer type.
- Steblay, Nancy Mehrkens (1992). "A meta-analytic review of the weapon focus effect.". Law and Human Behavior. 16(4): 413–424.
- Memon, Amina (May 2001). "On the "general acceptance’ of eyewitness testimony research: A new survey of the experts". American Psychologist. 56(5): 405–416.
- Eugenio, Paul (1990). "Weapon focus, arousal, and eyewitness memory: Attention must be paid". Law and Human Behavior 14: 167–184.
- Scott, B. (1976). "Eyewitness testimony and suspect identification as a function of arousal, sex or witness and scheduling of interrogation". Paper presented at the American Psychological Association Annual Meeting.
- Messos, Jane (1987). "Some facts about weapon focus". Law and Human Behavior. 11(1): 55–62.
- Pickel, Kerri (1998). "Unusualness and threat as possible causes of "weapon focus"". Memory 6(3): 277–295.
- Mather, Mara (1998). PDF "The weapon focus effect revisited: The role of novelty". Legal and Criminological Psychology 3: 287–303.
- Christie, John (2013). "Of guns and geese: A meta-analytic review of the ‘weapon focus’ literature". Psychology, Crime & Law. 19(1): 35–66.
- Yantis, Steven (1992). "Involuntary attentional capture by abrupt onsets". Perception & Psychophysocs. 51(3): 279–290.
- Jonides, John (1996). "Attentional Capture by Abrupt Onsets: New Perceptual Objects or Visual Masking?". Journal of Experimental Psychology: Human Perception and Performance. 22(6): 1505–1513.
- Truelove, Ronald S. (2006). "Do weapons automatically capture attention?". Applied Cognitive Psychology 20: 871–893.
- Leippe, M. R. (1995). "The case for expert testimony about eyewitness memory.". Psychology, Public Policy, and Law 1(4): 909–959.
- Cronin, Christopher (2009). Forensic Psychology: An applied approach. Kendall Hunt Publishing Company. ISBN 978-0-7575-6174-0.