Tools Used for Forensic Science
The word 'forensic' means 'pertaining to the law'; forensic science attempts to resolve legal issues by applying scientific principles to them and using scientific technology and procedures to aid in an investigation. As forensic science expands and grows in complexity, so do the techniques, tools and equipment associated with it.
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DNA Forensics
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Forensic biologists utilize DNA forensics to examine blood and other bodily fluids, hair, bones, insects, and plant and animal remains to help identify victims and support criminal investigations. Scientific techniques in DNA forensics include Restriction fragment length polymorphism (RFLP), polymerase chain reaction (PCR), short tandem repeat (STR), mitochondrial DNA analysis (mtDNA) and Y-chromosome analysis. Scientists use these forensic tools to identify specific DNA information and link it to an individual. Though scientists developed these techniques in the 1980s, they continue to enhance the technology.
Fingerprinting
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Tools such as fingerprint dust, brushes, gel lifters, fuming cabinets and ninhydrin allow forensic investigators to locate and identify fingerprints at a crime scene for use as evidence. Scientists and investigators have used fingerprinting technology for decades, but it is constantly improving, allowing prints to be obtained from surfaces that were previously nonobtainable. Because fingerprints are unique to each person, forensic investigators can use fingerprinting technology to identify who was present at a certain location based on the fingerprints found there. Ninhydrin is a chemical that reacts to amino acids to make fingerprints visible to the naked eye. Fuming cabinets use humidity and evaporated superglue to identify fingerprints.
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Chemical Sample Identification
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Chemical identification tools break down and analyze compound and chemical mixtures so scientists can identify individual chemicals. A variety of these tools exist and serve different purposes. For example, a gas chromatography/mass spectrometry (GC-MS) machine uses heat to separate and identify compounds present in blood (such as drugs) or chemical samples. A Raman Spectral Comparator (RSC) uses lasers to identify individual components of a chemical sample -- usually with ink and documents. Scientists use a glass refractive index measurement machine (GRIM) to compare glass samples based on their chemical makeup.
Detection of Blood and Other Body Fluids
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Investigators glean valuable information from a crime scene when they locate bodily fluids, such as blood, urine, saliva, sweat, semen and vaginal fluid. Forensic investigators use tools like ultraviolet lights and luminol to locate bodily fluids invisible to the naked eye. Luminol is a chemiluminescent, meaning it emits light during a chemical reaction. For example, although cleaned blood spatter may be invisible to the naked eye, applying UV light or luminol will make that blood spatter fluoresce and therefore visible.
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References
- All About Forensic Science: Definition of Forensic Science
- Labino: Crime -- UV and Body Fluids
- Explore Health Careers: Forensic Biologist: Overview
- Forensic Science: Tools of the Trade: Forensic Science Gear and Gadgets Source: The Tools and Techniques of Forensic Science Professionals
- Oak Ridge National Laborator; DNA Forensics; June 2009
- Tech FAQ: What is Luminol
Resources
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