Final answer:
If a DNA fingerprint of a suspect doesn't match the one from the crime scene, it indicates that the suspect is not the source of the crime scene DNA, suggesting the suspect didn't contribute to the sample and likely isn't involved in the crime.
Step-by-step explanation:
If a DNA fingerprint of a suspect does not match a DNA fingerprint from a blood sample taken at a crime scene, we can conclude that the suspect's DNA does not originate from the same individual who left the blood sample. DNA fingerprinting relies on identifying the unique DNA patterns that every individual, except identical twins, possesses. Technicians can compare these patterns to establish if two samples are from the same person or are related individuals.
Various techniques are used to create a DNA fingerprint, including gel electrophoresis, which sorts DNA fragments according to size, with the pattern of bands on the gel providing a unique identifier for an individual. Restriction enzymes cut DNA at specific sequences, and PCR (Polymerase Chain Reaction) amplifies DNA to get enough material for analysis. By comparing the suspect's DNA fingerprint to that of the sample from the crime scene, forensic geneticists can determine if there is a match.
Thus, in the context of forensic investigation, if the DNA fingerprints do not match, it suggests that the suspect is not the source of the crime scene DNA and is likely not involved in the crime in question. This is a crucial piece of evidence in the judicial process, determining the direction of an investigation and aiding in the exoneration or incrimination of suspects.