Fingerprint comparison
Historical information
The use of fingerprints for purposes of identifying criminals has been in use for a very long time. The history of fingerprint comparison traces back to the time Sir William Herschel demanded the fingerprints and signatures of the civil contractors in the District in India. In the 1980, the very first computer data base of fingerprints was developed and referred to as the Automated Fingerprint Identification System, AFIS (Sethi, Hazari & Inderjeet, 2016). Today, many people are identified through the fingerprints and national identity cards have the fingerprints for every person.
Uses and functions
Fingerprints are developed from the skin that covers palms of hands as well as soles of feet. This specific skin type is elevated into minute ridges. These tiny ridges usually follow patterns of definite and unique design for every human being. This friction skin is what leaves identifiable marks or prints that are normally used in establishing an individual through comparison (Smith, Mound, Brown, Leonard, Lovell & Bennett, 2017). Therefore, the basic use and function of fingerprints is to help in ascertaining whether a given suspect is the real offender. The taken fingerprints are normally compared to those of the suspect with a view of establishing any similarity between the two.
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Limitations
As a technique of carrying out crime investigations and establishing the real offender in a case, the use of fingerprint comparison has a number of limitations. Firstly, the crime investigators must have the suspect readily available for purposes of comparing the taken fingerprints (Roewer, 2013). Therefore, use of finger prints is limited to a case where the suspect is present. In the absence of the suspect, taken fingerprints are then rendered useless. The other limitation is that the fingerprints are easily distorted (Stevenage & Bennett, 2017).
Explain how it can be challenged in court
Since fingerprints are subject to easy distortion, they often lead to wrong identification of the criminal in a given case (Pena, 2013). A specific suspect may incidentally have fingerprints that are similar to the distorted ones hence lead to incrimination of the wrong person. Based on this argument, it is possible to challenge the use of this technique in a court of law. Application of fingerprint comparison is seen in the identification of the person who commits murder using a knife.
DNA analysis
The use of DNA analysis in criminal investigations has also been in existence for a very long time. It is vital to note that DNA profiling and analysis was developed by Professor of Genetics known as Sir Alec Jeffreys. DNA testing was introduced in the field of criminal investigation in the year 1985. This testing is based on the biological parts like hair, skin and blood. The first person to be subjected to DNA testing as part of crime investigations was Florida rapist Tommie Lee Andrews. He was successfully convicted in a case that was largely premised on the DNA evidence.
Uses and functions
The main use of DNA analysis is finding out whether a given suspect was involved in the act of crime or not (Ostojic & Wurmbach, 2017). Hair, blood or small skin part got at the scene of crime may be tested with a view of establishing its DNA nature. If the tested DNA resembles that of the suspect then it confirms that he or she is the real offender.
Limitations
The use of this technique is limited to cases where the suspect is readily available in order to give his or her DNA tests for matching (Hargreaves-O’Kane & Dixon, 2014). Moreover, the use technique is also limited to scenarios where a biological part of the human body is found at the scene of the crime for DNA testing and comparison.
Explain how it can be challenged in court
This technique is vulnerable to fake DNA test outcomes (Butler, 2015). Most people fake DNAs. A criminal may plant fake DNA evidence in his or her body. Based on this point, it is possible to challenge this technique in court. An example of DNA analysis application is the evaluation of semen found on a girl to ascertain the real person who committed the rape act.
References
Butler, J. M. (2015). The future of forensic DNA analysis. Phil. Trans. R. Soc. B , 370 (1674), 20140252.
Hargreaves-O’Kane, M., & Dixon, J. (2014). Advances in Fingerprint Techniques. Advances in Forensic Human Identification , 305.
Ostojic, L., & Wurmbach, E. (2017). Analysis of fingerprint samples, testing various conditions, for forensic DNA identification. Science & Justice , 57 (1), 35-40.
Pena, S. D. (Ed.). (2013). DNA fingerprinting: state of the science . Springer.
Roewer, L. (2013). DNA fingerprinting in forensics: past, present, future. Investigative genetics , 4 (1), 22.
Sethi, S., Hazari, P., & Inderjeet, R. K. (2016). DNA Fingerprinting technology: An exhaustive review. Bio-Chemiae Acta , 1 (1), 35-39.
Smith, P. A., Mound, S., Brown, N., Leonard, R., Lovell, C., & Bennett, S. (2017). Empirical approaches to improving the use of DNA in crime scene investigative practice. International Journal of Police Science & Management , 19 (1), 54-60.
Stevenage, S. V., & Bennett, A. (2017). A biased opinion: Demonstration of cognitive bias on a fingerprint matching task through knowledge of DNA test results. Forensic Science International .
