Thursday, March 12, 2009

DNA Helps to Solve Crimes!

Crime scene investigators often look for fingerprints, blood types, and protein profiles to help solve crimes. Fingerprints are unique to each person and they are difficult to find a perfect print at a crime scene. Blood found at a crime scene can only show that there may be a connection between the suspect and the crime. Every individual’s blood is categorized into classifications such as type A, type B, type AB and type O. Although some of these blood groups are found more common than other individuals it can’t prove that because the suspect has the same blood type found at the crime scene they were the perpetrator. There is always something left behind in a crime scene from the criminal, it is just left up to the investigators to look for clues. For example, crime scene investigators look for clues that provide DNA evidence such as hair, saliva residue, or cells from fingernail scrapings. Due to the fact that DNA is unique to each individual, the evidence is used in courts to convict people. However, if the crime scene is not properly secure and the protocol to ensure evidence is tampered with, then the evidence may not be admissible in court. Once evidence is collected the technique polymerase chain reaction is used. For fingerprints the length of the of the DNA sequences vary amount people and can distinguish one individual from another. This technique is used to compare individuals directly to see if they match or not. It is best to use the DNA from the nucleus of cells. Mitochondrial DNA can be extracted from dead samples and can be easily mutated, thus making DNA from the nucleus of cells better for analysis.

Polymerase chain reaction: a process that copies a small segment of DNA millions of times to obtain a sample large enough for analysis.

My Reaction
I think the fact that technology has progressed so significantly that crimes are able to be solved by molecular cells is amazing. Unfortunately, I know I personally like shows such as CSI and it really does provide a false truth as to what the crime scene investigators are capable of doing at crime scenes in a small amount of time. I think if technology keeps progressing it will provide an advantage for victims whose criminals who have not been yet convicted. It is also important to make sure that people know the unrealistic things that crime scene investigators can do because families who have been victim to crime get upset when they set standards that are too high and unrealistic for the those trying to help solve the crime.

No comments:

Post a Comment