DNA Analysis in Murders

In order to identify people, fingerprints were used as the main identifiers.  Since fingerprints are unique, it’s very unlikely that one person will have the same fingerprint as another.  With further developments in science, however, DNA can now be used as identifiers as well.  When fingerprints are unavailable, a simple saliva test for DNA will do the trick.

With regard to criminal cases like murder for example, DNA analysis has become a very useful tool.  It’s an effective means for identifying victims as well as singling out the perpetrator.  In murder cases, police document all the evidence in the crime scene and endeavor to look for DNA evidence too.  They find the evidence using two methods.  One is to look for the victim’s DNA on the perpetrator’s person.  The second method is to look for DNA evidence of the perpetrator on the murder victim.

Essentially, 99.9% of DNA sequences in humans are similar in every person, there’s enough DNA that’s different to distinguish one from another.  With a single DNA strand, it’s possible for law enforcement to determine if the perpetrator is male or female.  The main thing that the police have to look for with DNA evidence is that there should be relevant amounts of bodily fluids from the perpetrator to the victim and vice versa.  With insufficient data, the murder case has to be solved using other pieces of evidence.

If there was a struggle before the murder happened, it can be the case that the victim scratched the perpetrator and therefore, the police with have some skin and blood left under the victim’s fingernails to work with.  What if a gun was used in the murder?  It’s highly unlikely that there was a struggle enough for the perpetrator to leave DNA on the victim.  For this particular situation, suspects of a murder will have to be tested for the victim’s blood on their clothes, shoes, etc.

With DNA analysis, there’s a bigger chance that criminals will be brought to justice.  In violent crimes like murders, it’s easier to establish that the perpetrator was in the scene with DNA evidence to work with.