Crime and DNA tests

DNA testing is an evolutionary crime-solving tool with a  powerful potential to help figure out how and who committed crime. The use of advanced scientific techniques in testing crime scene evidence has help resolved many previously unsolved crimes and has contributed to the arrest and sentence of rapists and other violent lawbreakers. However , DNA testing has made it possible to release prisoners that were wrongly convicted for crime they did not commit. In his article, Fathi approximates that at least 232 innocent persons who had been wrongly pronounced guilty have been exonerated including 17 who had been condemned to death for criminal offense they never  committed (Fathi 2009).DNA profiling  also known as DNA testing is a technique utilized by forensic scientists to help in the identification of people on the basis of their various DNA profiles. Different individuals have different DNA profiles which are encrypted sets of numbers that mirror an individual DNA makeup, which can be used by forensic scientist to identify people.

The potential of DNA tests

DNA testing has one of the huge benefits, as it can establish without doubt a person's genetic make-up and unique identity. The DNA test is often used to solve crimes from decades ago when forensic science simply wasn't as advanced. As well as identifying criminals or victims of crime, the DNA test can also come into play when it comes to crimes made in the name of spiritualism or religion. For a long time objective scientific evidence has been regularly used to look into crime. Even though most crimes continue to be solved by confessions and eyewitness

Accounts, forensic evidence such as drugs, blood, firearms, fingerprints and even semen have emerged as a means of establishing truth. Advances in technology have propelled DNA testing to become an accomplished part of criminal justice procedure and thought amidst early controversies and challenges by defense lawyers, the use of DNA results in courtrooms has increased over years (Hails 2008).

Exoneration of Jerry Miller

After spending 25 years, Jerry Miller was exonerated from an Illinois prison for rape. Jerry was found guiltless after DNA evidence proved that he was not responsible for the 1981 attack and the judge has to vacate his conviction. Miller, now aged 48, had been ascertained “guilty of rape, robbery, aggravated kidnapping and aggravated battery”. Nevertheless, he was paroled in March 2006 and now is employed with two jobs and stays with a family member (MSNBC).

Usually, misidentification by witnesses leads to wrongful convictions of people like Jerry Miller who end up serving sentences they do not deserve. Instances in which inmates have been exonerated over the last ten years have increased (Hails 2008)

DNA Testing Technologies

There are numerous techniques in used for DNA testing based on the fact that individuals DNA sequence are never the same. Some technique may have been used to prove innocence to exonerated inmates.

RFLP test

This text entails the extraction of  DNA is and cutting by enzyme into restriction fragments, which are suspended in a gel, divided up by size, and channeled from the gel by blotting onto a membrane. Identification is done by radioactively labeled probes and the membrane is placed over an x-ray film which produces a picture of the DNA fragments, called an "autoradiogram." A match is then made with DNA from an evidence stain and those from a suspect's sample DNA are found to be the same. Lack of much may imply that the suspect was not involved in the crime.

PCRThe use of this method involves the use of preparation of samples in which the targeted DNA is copied many times. Two DNA molecules are usually are produced from the initial molecule each time the test is done. This method permits the analysis of as little as a single copy of DNA. The DNA sequence can then be compared with that of the suspect. Lack of similarity may call for exoneration.


The test is faster than RFLP, and the analysis can be done with a number of different automated and semi-automated methods. This test makes it possible to amplify regions of the DNA molecule that display variation in DNA fragment length between .The forensic communities prefers smaller fragments of DNA. Matching of the DNA in the samples and that of the suspect is carried with possibility of an inmate being released in case of mismatch (DNA Forensics)


Recent advances in forensic DNA testing have extended the types of useful biological evidence such as blood, saliva, bones and semen. Availability of DNA testing technologies has made it possible to determine criminals and offenders of crimes such as murder and rape. This ensures that not only the guilty face justice but also those initially convicted are exonerated. It is most likely that the use of DNA technology will continue to find its use in the forensic labs as well as the courtrooms.

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