Tools of the Trade: Forensic Science Gear and Gadgets
When forensic scientists arrive at a crime scene, they have a tough job ahead of them. The scene must be documented according to strict standards, and each piece of evidence recorded. The evidence of the crime might be large and noticeable, like a gun or marks in a door, but it could also be microscopic and near-impossible to detect. Luckily, the scientists come armed with a range of tools to help them identify and analyze even the tiniest fragment of evidence. After this analysis at the scene of the crime, samples are taken to the forensics laboratory, where even more powerful equipment can be used to decipher the clues.
Scanning Electron Microscope
The scanning electron microscope is a high-powered microscope that produces images by measuring electrons rather than light. It allows for the quick analysis of tiny bits of hair, clothing, and other particles of crucial evidence.
Ultraviolet Lamp
Some types of evidence can only be seen using an ultraviolet light. Investigators often use UV lamps to uncover remnants of bodily fluids, such as blood, that contain fluorescent particles.
Electrostatic Dust Print Lifter
At a crime scene, one of the most delicate types of evidence is impression evidence. Faint patterns of dust, left by shoes or tires, can be revealed by electrostatic dust print lifters, which use an electric current to attract the dust to a thin, metallic sheet.
Gel Lifter
Another way to identify fingerprints, dust prints, and other prints is to use gel lifters. The gel is simply pressed onto a surface, and dust and other trace elements stick to it.
Cast
Three-dimensional impressions, such as footprints and tire tracks, can be preserved using casting. While casts are often made of prints in soft soil, they can also be made from impressions in snow.
Camera
Everything at a crime scene needs to be thoroughly documented. Some investigators take extensive written notes, while others use high resolution cameras to record the scene visually.
Swab
Different types of swabs are used to collect different kinds of evidence. Swabs are often used to take DNA samples.
Ninhyrdin
Ninhydrin can be applied to various surfaces to make fingerprints visible. The chemical reacts with amino acids and thus makes the residue from a finger detectable.
Scalpel
Scalpels and other types of blades are always useful at crime scenes. A technician might use one to cut out a piece of carpet that has dry stains on it. A more thorough analysis can then take place in a laboratory. Of course, coroners also use scalpels when conducting autopsies.
Gunshot Residue Kit
Forensic techs can determine whether or not a gun has been shot recently by using a gunshot residue kit. Field kits can produce results within a few minutes, which can later be verified by more extensive testing in the lab.
Gas Chromatography-Mass Spectrometry
A gas chromatography/mass spectrometry (GC-MS) machine is capable of breaking down and identifying complex compounds. GC-MS machines are often used after a fire has occurred to detect accelerants, which indicate arson. They can also be used to identify the presence of drugs in a blood sample.
Raman Spectral Comparator
Like GC-MS machines, the Raman Spectral Comparator (RSC), breaks down compounds and allows for the analysis of the individuals components. The RSC process uses lasers, and is primarily applied to documents and inks.
Glass Refractive Index Measurement
The glass refractive index measurement machine (GRIM) is used to compare glass fragments. The fragments are mixed with silicon oil and heated. A computer can then calculate the refractive index of each piece of glass. If the refractive index is the same, then the fragments came from the same source. This process is often used to compare glass from a broken window with glass combed from a suspect's clothing.
EFIT
Sketch artists have been producing images of suspects, as described by witnesses, for many years. Many forensic teams are now adopting EFIT, a computerized composite database for facial identification. Witnesses can describe a suspect to a forensic artist, and an approximate likeness will be produced using this program.
Fuming Cabinet
Most fingerprinting methods use some sort of chemical or lifting process. Another process involves placing an object into an airtight fuming cabinet. The humidity in the cabinet is increased, and evaporated superglue is introduced. The glue sticks to the fingerprint residue, making it visible.
Photos courtesy of: Brittanica, Flashlight Maniac, Maine.gov, HowStuffWorks, TechShout, Isohelix, Oklahoma State Bureau of Investigation, Media Assassin, Carolina, Office of the Attorney General, University of Lincoln, University of Lincoln, Footprints, AirClean Systems.
Sources: Purdue University, MiniScience.com, Projectina, Evident Crime Scene, TruTV, Crime-Photo.com, TreMonti Consulting, Forensic-Evidence.com, Evident Crime Scene, Arrowhead Forensics, Bronx Science, Association of Certified Fraud Examiners, University of Lincoln, New England Press, Inc., University of Lincoln.
