DNA: Easy Evidence?

One of the biggest misconceptions about police investigations is the idea that DNA evidence is both easy to find and is easy to use. Every television show on the topic has DNA evidence at every scene, and after maybe a day or two, the forensics squad finishes analyzing it and finds who was present at the scene of the crime. However, that isn’t how it works in the actual world.


First of all, it takes more than a few seconds of swabbing to even find DNA evidence that would be passable in court. There can be DNA from anyone who has been near the crime scene tainting any evidence, including police that aren’t careful enough. DNA comes from anywhere, and isn’t always good to analyze. Also, with every cop show on TV using DNA evidence in every episode, criminals are taking more care in modern times to not leave any (a side effect of the genre.)

In addition, it takes more than a few days to process samples. It normally takes a couple of months to finish the DNA testing, can take up to a year and sometimes cases are even resolved before the DNA evidence comes in. I can’t even hope to explain the science behind the testing, but suffice to say it is very complicated, its not as simple as plugging the sample into a computer that will analyze it overnight.

The problem with the public misconception surrounding DNA evidence is that both the public and jurors are biased in their expectancy of DNA evidence. Since it is extremely hard to analyze, when mistakes are made (and they are made,) it is a lot harder to refute. It also makes people more inclined to be cooperative with police with the hopes that DNA evidence will prove them innocent, but in reality the free talking with police only helps to incriminate them more, especially if/when DNA evidence isn’t found, or rarer, there is a mistake and it makes them seem guilty.

3 thoughts on “DNA: Easy Evidence?

  1. Ashley Elizabeth Day

    I really found your blog interesting. I could definitely relate to it. Sadly a shooting happened on my street in a quiet suburban neighborhood in Pennsylvania that lead to a homicide of a 46 year old mother of 4. The event literally just happened a few days ago early Tuesday at 1:00 AM. That same morning in class I got many texts from concerned friends asking what was going on, but in all honestly I had no clue. I quickly called my mom and went on our local news website to get any information I could on the incident. I wasn’t even home when the event happened but I was shook up about it. My mom informed me on the news and said our street was shut down and a portion of it is still shut down today. She said that thousands of cop cars and “CSI type” trucks were outside the home. Many detectives and men wearing booties and protective gear were going in and out of the house collecting evidence. That image popped in my mind when I read your post. I then asked myself if they found any DNA evidence and considered how long it was going to take to process all of it after I read your blog. Thats the truth in DNA you can’t rush it, it will eventually paint the picture for you in time. A sadden community is looking for answers in this not random shooting that occurred, I hope in time that we can get the answers we need from DNA to find justice for the woman and family who lost their mother. Click here to read about the horrible tragedy and watch a video on it as well.

  2. dnp5145

    I love to watch shows that tend to incorporate DNA testing such as NCIS or CSI. Although I knew that the shows were always fiction, I had always though that there were parts of the show based on real life including this. I never really thought about how time consuming the process for DNA testing was as well as how much there is behind it. This leads me to wonder how many people have a misconception of DNA testing due to television shows and films? I can’t believe that I am the only one especially in a world where television and films are so popular. Also, how can we let people to become more informed?

  3. Corbin Kennedy Miller

    I took a forensics class my senior year of high school and I remember learning about this. If you go back to the OJ Simpson trial, the main reason the prosecution wasn’t able to get him behind bars is because the police had tainted the evidence at the scene of the crime. As for the public’s views toward the crime scene analysis process, it is known as the CSI affect, which is how the media portrays the process compared to the real word. You can read more about it in this link, it’s a very interesting topic. (http://www.nij.gov/journals/259/pages/csi-effect.aspx)

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