DNA and Fingerprints

Author's Note: This is my science essay written to inform you on the good and bad sides of DNA fingerprinting.

Have you ever wondered how the police catch a perpetrator? Well there is and it is a completely safe and easy technique. Instead of using methods of blood testing or trying to get an accurate picture of a criminal, there is an easier way to catch them. It is called DNA fingerprinting.

            First of all, most people know what DNA looks like, but do they know what it is really made of? Most of the time, the answer is no. The swirling backbones are called nucleotides and they are made of a base, sugar, and phosphate. Connecting the two strands are the base pairs. There are two different kinds of base pairs and they are guanine and cytosine, or adenine and thymine. These backbones and base pairs combined make the swirling shape that most of us already know. DNA stands for deoxyribonucleic acid. As we learned in science class, the DNA is located in the nucleus of a cell. There “The typical fingerprint may have as many as 150 ridge characteristics” (Salter). This is what makes all fingerprints unique. There is not two people that have the same print.

Moving on, DNA is one of the most commonly used sources of evidence from break-ins, murders, or robberies. Lots of times, the criminal does not leave blood behind his/her scandal, so the police go to another option which could likely be fingerprinting. If there is any blood, the case is basically solved but there is the fear of it being contaminated. This means that fingerprinting is very clean and easy. If for some reason you would need to get a person’s fingerprint, there is lots of paperwork you would need to do to get it. Some of this includes lots of fees, time limits, and approval from the person whose print you want. The process of finding the person you are looking for just by getting their DNA is fairly easy. It starts out as the finding of a print. After you collect the evidence, you scan it into a computer that will store it and convert into a binary code (“computer language” of only 1’s and 0’s). Once it is converted, it will be matched to an identical print but if there is no match, it will just be an update to the system.

Lastly, fingerprinting is not the only way of collecting DNA though. Some of the more complicated methods are getting DNA from blood on a piece of broken glass or probably the most complicated way of catching a bad guy, trying to get an accurate picture and track him down. Blood testing is more difficult than fingerprinting because it uses specific amounts of blood instead of just an ink pad and a thumb. “Contamination can influence PCR results, particularly in the absence of proper handling techniques and proper controls for contamination” (Riley). On the other hand when you are looking at security footage of a break in, the burglar might be wearing a mask or hood and you are unable to see his face. If you can’t get an accurate picture, you can’t use the picture technique. Anything the delinquent touched with his/her bare hands will have his/her print on it.

Without fingerprinting technology, the FBI or other police forces would have to resort to challenging and risky techniques to collect DNA. Now that you know the risks and advantages about fingerprinting and some background info on DNA, it might come in handy to know what is happening when a crime scene occurs.

 

Riley, Donald E. DNA Testing: An Introduction For Non-Scientists. 2005.

Choi, Charles. DNA Extractable From Fingerprints. 31 July 2003. 21 March 2012 <http://www.fdiai.org/articles/dna_extractable_from_fingerprint.htm>.

Salter, Debbie. Fingerprinting - an Emerging Technology.

"What is DNA?" 16 April 2012. Genetics Home Reference. 16 April 2012 <http://ghr.nlm.nih.gov/handbook/basics/dna>.