DNA aids forensics scientists a great deal. As all their work circles around DNA, they cannot do anything without DNA. As the structure of DNA and the arrangement of the nitrogen bases is what determines a person’s phenotypic traits, a forensics investigator can use the blood, hair, or any bodily fluid containing DNA to determine who has committed a crime.  If blood is found at the scene of a murder that does not belong to the victim, it could belong to the murderer. This means only the criminal will have DNA with that specific structure, and suspects can be tested to determine who the guilty party is.