DNA in Criminal Investigations

The material that governs the inheritance of the traits of living things is known as DNA. This is found in body parts like bones, hair color, and eye color. DNA is described as being long and narrow and resembles a thread. This string is said to be very narrow, the approximately 1/millionth inch on each side. The human being’s cells contain DNA. This could be in brain cells, liver cells, sperm cells, and other body parts. A body part contains a DNA that is similar in all other cells of this body. Critical to note, red blood cells do not have DNA. In this case, the blood is typed since the white blood cells contain DNA material. Besides, it should be noted that plants and bacteria also have DNA (William, 2001).

Forensic experts rely on DNA testing to establish various things while identifying suspects through the evidence left at the scene of the crime. Another use is exonerating people who have been accused wrongly. In cases of catastrophes, this testing is done with an aim to identify victims. In families where parents want to identify paternity, DNA testing helps to give out results. Poachers are also prosecuted through this testing. In cases where a certain bacteria are thriving, DNA test helps in detecting an organism that could be a threat to human survival. In the medical field, doctors use the technology to identify a potential donor in transplants. DNA testing is useful in accessing the breeds to use in livestock or plants.

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The notable case where DNA testing was done was after the September 11 attacks. The forensic experts carried the tests to identify victims and their relatives. The main DNA testing has been through RFLP and PCR, what requires large amounts of DNA. This, therefore, means that in a crime scene where the material is old and in small quantities, RFLP is simply not applicable. In cases where the condition of the DNA is moist and warmth, then DNA material degrades and RFLP is not applicable as well. PCR testing has replaced RFLP due to the fact that it requires less DNA. Any contamination interferes with the results of the DNA in cases where the materials were handled poorly.

Although PCR is more prone to error than RFLP, forensic experts prefer to use PCR due to the speed and sensitivity involved during testing. Currently, forensic experts use STR (short tandem repeats), this is where the sequence of DNA repetition is followed to establish a person. DNA testing has had a significant role in the criminal justice system. Before the introduction of DNA testing, the investigators were heavily relying on evidences and eyewitnesses. However, this technology is much better than the witnesses. Through this evidence, many convicts on death row have been exonerated. Besides, such evidences make it much easier to identify culprits behind rapes and murder. As a result, many innocent people have been freed, and otherwise, the innocent would have been executed by mistake.

Modern DNA testing has greatly supported the accuracy of issuing capital punishments. It is ensuring that the guilty are the punished. Although capital punishment is debatable, this technology has helped to administer death penalties fairly. DNA is now replacing fingerprinting. If collected and preserved carefully, these results can be used in the future identification since one’s DNA does not change. According to the report by National Institute of Justice (1999), DNA testing has been widely accepted in most countries. Many Law authorities have introduced databases to make the identification much easier. Establishing of a database has ensured that the crimes that seem to be unrelated are linked to identify a suspect who is unknown to the authority.


The criminal justice system is now confident when identifying a suspect. The use of DNA testing is more accurate than the use of a genetic marker. It ensures stability while avoiding errors. Although DNA testing has greatly revolutionized the justice system, it has had a negative impact on the judicial system. When the results appear inconclusive, they are considered to be useless and time-wasting.(Hart, 2006)

A convict seeking DNA test is stereotyped to be guilty. The cost incurred during this process is a big burden to the justice systems that are already straining with their budgets. In cases where crimes occur without any sample available for testing, it is likely that a wrong conviction will happen. DNA testing is limited in some countries; this means that the inmates’ verdicts could otherwise have been changed by the DNA results. Poor preservation of biological evidence has led to insufficient results. All in all, DNA testing has solved the mystery of establishing one’s identity.

DNA testing is very effective when used efficiently. It has greatly helped in creating numerous databases, which makes the identification of criminals easier, just like examining the fingerprints. Databases have helped in reducing costs; this is in terms of the money that would have been used for the investigation and incarceration. The innocent people have also been freed of any charges thanks to the forensic work. (Saferstain, 2011)