Collection of evidence (Cognitive)

Eyewitness Testimony

Eyewitness testimony can provide crucial evidence in criminal investigations. However, it’s important to be aware of its potential unreliability. Factors such as stress, leading questions, and reconstructive memory can influence the accuracy of testimony.
One technique to improve the accuracy of eyewitness data collection is the Cognitive Interview. This involves strategies like reinstating the context, changing the narrative order, and changing perspective.
Research by Loftus and Palmer highlighted the misinformation effect, demonstrating how leading questions can create false memories or distort an eyewitness’s recall.

Interrogation and Confessions

Interrogation techniques can also yield important evidence. These methods, must however, be employed ethically and judiciously to avoid false confessions.
The Reid Technique is a controversial method, often resulting in criticism as it may lead to false confessions due to its accusatory and confrontational nature.
In contrast, the PEACE Model (Preparation and Planning, Engaging and Explaining, Account Clarification, Closure, Evaluate), which is information-gathering rather than accusatory, is generally considered more ethical and reliable for extracting true information.

Lie Detection

Lie detection tests such as the polygraph measure physiological responses (like heart rate, blood pressure, and skin conductivity) to detect deception. However, their reliability is questionable as they detect anxiety which can be caused by various factors, not just lying.
Newer methods of lie detection, such as Brain Fingerprinting, use EEG to identify brainwave responses related to recognition. While potentially promising, these techniques are still under evaluation for their reliability and validity in real-world settings.

Memory Retrieval Techniques

More controversial methods, like hypnosis or the use of truth drugs, aim to assist in retrieving deep or repressed memories. The scientific consensus, however, leans towards these methods as unreliable and potentially harmful, able to create confabulations or false memories.

Remember, while these cognitive methods can yield fruitful leads, they require rigour and ethical considerations due to their potential to cause false memories or coercion. A critical and informed understanding of cognitive processes, biases, and vulnerabilities are fundamental to their effective application in criminal investigations.