If you have been implicated in a crime due to the presence of your finger prints or DNA, please contact the Clearwater criminal defense lawyers of the Law Offices of Tragos, Sartes & Tragos, PLLC at 727-441-9030.
Fingerprints are one of the best forms of physical evidence that police and investigators can get from a crime scene. They can conclusively identify victims and offenders. In addition to identifying a person, they can tie the offender to the scene.
Databases which used to be maintained on a department by department basis are now nationalized. In addition, they have been computerized which allows for extremely quick searching on a national, state, or local level.
Processing Fingerprint Evidence
There are a number of methods of processing for fingerprints. There are two basic principles on which the entire concept rests:
- Friction ridge patterns don’t change. Friction ridge patterns are the swirled patterns in the tips of fingers. Everyone has them.
- 2. No two people have the same pattern of friction ridges. Just like, generally, no two people have the same DNA. This makes it exceptionally easy to identify a person, if their fingerprint is on file.
People’s fingerprints can be on file for a variety of reasons. They can be collected when an individual is arrested, for future reference. A person’s prints are often taken when they start a job in a certain occupational field. Also, parents are increasingly asking schools and local police departments to fingerprint their young children. This is because children who are abducted or are the victims of other heinous crimes often cannot be identified without these prints.
Fingerprints exist because of the tiny pores in the friction ridges. These pores release sweat which mixes with other body oils and dirt. When the oils, sweat, and dirt mix together, the fingers produce prints on smooth surfaces. To get to these prints, detectives use special powders and chemicals to make the prints appear.
The visibility of a set of prints depends on the surface from which they’re lifted. As the technology in every other field as improved, so has the technology for collecting fingerprints.
In the past few years, there has been a large increase in the use of DNA evidence. This evidence has been exceptionally useful for not only convicting people but also for removing wrongly convicted individuals from prison.
DNA, deoxyribose nucleic acid, is the blueprint for every cell in an individual’s body. It is found in every skin cell, every strand of hair, and every bit of anything that is made of cells. DNA forms a long, twisting chain that forms a double helix. It looks complicated but is made of only four nucleotides. These four nucleotides form a distinct pattern for every person. The four nucleotides are Adenine, Cytosine, Guanine, and Thymine.
The four nucleotides form pairs. Adenine and Thymine will link together and not with Cytosine or Guanine. The same holds true for cytosine and guanine. Because of this, if people have a partial strand of DNA, they can figure out what goes on the other side of the ladder based on what nucleotide is visible. The vast majority of DNA is identical from human to human but 3 million base pairs are unique to each individual. It is these base pairs that allow for DNA testing to pin an individual to a crime or crime scene or to free an individual from a crime.
How DNA Evidence is Used
DNA evidence depends on being able to compare the DNA from a suspect to the DNA from the crime scene. Sometimes, investigators have DNA from the crime scene but not a suspect. In these instances, they can compare the crime scene DNA to all of that which is found in CODIS. CODIS is a DNA sample database that is maintained by the FBI.
When using DNA in a crime scene, investigators prefer to use non-coding DNA strands. This makes it easier to determine whether or not there is a match. In general, the same tests used to determine paternity are used to match DNA sets for crimes.