What is forensic psychology?

Forensic psychology is the combination of psychology and law. It is the application of psychology in legal settings.

Forensic psychology, as defined by the American Psychological Association, is the application of clinical specialties to the legal arena. This definition emphasizes the application of clinical psychology to the forensic setting.

Christopher Cronin, who has written a well-known textbook on forensic psychology, defines it as The application of clinical specialties to legal institutions and people who come into contact with the law

Need For Forensic Psychological Tools

Forensic psychological tools include those instruments whose application can result in detection of crimes. These tools can be utilised to recognize the culprit from among the suspects as soon as possible.

Innocent persons can be prevented from being convicted falsely, which is a serious issue since decades immemorial. Individuals committing serious offences get away without getting convicted simply because of lack of evidence and it encourages them to become recidivists.

As a result crime rate is on the increase. According to the National Crime Records Bureau, the crime rate (crime incidence per 100,000 of population) in India increased from 383.5 in 2018, 385.5 in 2019 to 487.8 in 2020.

Forensic Psychological Tools

Some of the prominent and most used forensic psychological tools in the process of investigation are Polygraph, Behavioural Electrical Oscillations Signature Profiling, Layered Voice Response, Eye Detect, Suspect Detection System etc.

Each one of these instruments are most of the time effective in detection of culprits and can be used together to confirm detection if any doubt exists. These instruments are a very useful aid in the investigation process.

Today when the crime rate is increasing more and more and with the advent of technology in the commission of crimes such investigation techniques are a necessity.

How does the polygraph work?

The polygraph has 4 types of sensors. One is used for the recording of respiration rate, another is used for the recording of the increase in blood pressure, another one is used for detecting the oxygen consumption and last one is used for detecting skin resistance. All these type of sensors are used for the detection of culprits and innocents.

Brain Electrical Oscillation Signature Profiling

This instrument is used to detect whether an individual has any experiential knowledge in the commission of crime. Only an individual who has committed a crime will show experiential knowledge. This instrument is the most effective and scientific one till date. Here the culprit can't manipulate anything.

Layered Voice Analysis

This machine detects changes in emotions in a person's voice, like, for example- whether the person is under high stress or there is stress relief etc. It detects those emotions in a person's voice that are below 10ms and that can't be controlled voluntarily.

Eye Detect

This instrument works by detecting changes in eye movement and other minute changes such as pupil dilation and different types of eye expressions. This is a new instrument used in crime investigation.

Suspect Detection System

This instrument uses Galvanic Skin Response as a sensor which is used to find out changes in skin resistance under stressful conditions and this technique is used for detection of criminals.

Conclusion
Use of these techniques have to be increased. Increasing use of these techniques will lead to more detection, conviction and swiftness in solving a criminal case.

References:

• Baran, Vogel, M. J. (2016). Inconclusive: The truth about lie detector tests. APMreports.
  Published. https://www.apmreports.org/story/2016/09/20/inconclusive-lie-detector-tests
• Ginton, A. (2012). Estimated Accuracy Of CQT Polygraph Examination.
  A Non-Standard Method for Estimating Accuracy of Lie Detection Techniques. Published.
  https://www.academia.edu/11945504/ESTIMATED_ACCURACY_OF_CQT_POLYGRAP

Written By: Sohini Basu