DNA

DNA

DNA

DNA is contained in blood, semen, skin cells, tissue, organs, muscle, brain cells, bone, teeth, hair, saliva, mucus, perspiration, fingernails, urine, feces, etc.

DNA is really a code, divided up into sections. Dr Matthew Hodgkin, a Research Fellow at Birmingham University's Institute of Cancer Studies explains: “You may have heard the term 'double helix'. This describes the DNA molecule. It is two strands coiled round each other. You inherit half your DNA from your mother and half from your father. The genes are all in pairs and which of each pair you inherit from each parent is randomly determined when the egg or sperm cells are developing. This explains why an inherited disease caused by one gene will only be passed on to children in 50% of cases."

DNA tests are extracted by analyzing the pattern of strips that occur. If they are similar, there is a very strong chance it is a match. DNA is easily found in every cell in the body and for each person it is entirely unique unless there are identical twins. A variety of sources like blood, seamen, tissues, chemically treated tissues, hair root, saliva, urine, and products of conception are all used for DNA testing. When a crime is committed, a criminal will always leave behind a piece of himself. The reason DNA is not so readily available is because more than likely the police or environmental factors (heat, sunlight, moisture, bacteria, and mold) will contaminate the scene. Forensically valuable DNA can be found on evidence that is decades old, but the risk of contamination is high. Just like fingerprints, DNA testing cannot tell officers when the suspect was at the crime scene or for how long. DNA does more than just identify the source of the sample; it can place a known individual at a crime scene, in a home, or in a room where the suspect claimed not to have been. It can refute a claim of self-defense and put a weapon in the suspect's hand. It can change a story from an alibi to one of consent.

DNA profiling or fingerprinting was developed in 1984 by British geneticist Sir Alec Jeffreys and first used in forensic science to convict Colin Pitchfork in the 1988 Enderby murders case.

A DNA fingerprint is the same for every cell, tissue and organ of a person. This DNA fingerprint cannot be altered by any known treatment.

It makes sense that DNA evidence has become such a powerful crime solving tool because no person's DNA fingerprint is the same except for identical twins. This means that DNA collected from a crime scene can either link a suspect to the evidence or eliminate them which is why accurate DNA fingerprinting is critical as a crime solving tool.

Crime Victims can be Identified and Crime Scenes can be Linked through DNA Profiles

Crime victims can be identified through DNA from relatives, even when no body can be found. And when DNA evidence from one crime scene is compared with DNA evidence from another, those crime ...