Crimes are rarely solved exclusively by police patrol officers, although they are usually first to arrive on the scene. Often, they are accompanied and assisted by detectives, medical examiners, and crime scene investigation units to investigate, conduct post-mortem analysis as needed, and document the crime scene, respectively. The latter, in particular, plays a key role as forensic scientists gather and analyze information that is oftentimes vital to the resolution of the case and the rightful apprehension of the perpetrators.
Television shows like CSI, NCIS, and other crime procedurals have made forensics a household topic. And while these shows make it seem like cases can be solved in a matter of days, the truth of the matter is that forensic scientists use a combination of scientific procedures, medical theories, and apparatuses to unravel the mysteries of a crime scene—an overall process that could take a very long time. Here’s a look at some of the tools that forensic scientists use in their craft.
There are a lot of trace evidence that can be gathered from a crime scene. Things like hairs (both from humans and animals) and feathers, soil, paint, gunpowder residue, carpet fibers, flame accelerants, glass fragments, even pollen grains may be transferred between people, objects, and the environment during a crime. These things, in turn, can be used to implicate a suspect or find a missing person, among others.
Mass spectrometers are used to analyze trace evidence by determining the composition of such substances. This information can, for instance, lead investigators to a specific location, say a carpet maker who uses a particular mix of dyes or a nearby plantation that grows a specific kind of flower, helping police investigators identify and build a case against suspects.
Another important tool in a forensic laboratory is a microscope, since most of the evidence collected in crime scenes are minuscule and cannot be easily identified or analyzed by the naked eye. With the help of high-powered microscopes, these tiny pieces of evidence can be viewed more clearly and can thus be more easily identified. These microscopes are often outfitted with motorized linear stages for precise motion control, especially for particularly minuscule samples or those that don’t have even surfaces.
Simply put, chromatography is the science of separating mixtures down to their individual components in order to identify them correctly and associate a person with a specific piece of evidence. For example, chromatography may be used to determine if a dead person did indeed suffer from a natural heart attack or was injected with a drug that triggered the cardiac arrest. Depending on the evidence collected, forensic scientists may use different procedures—like thin-layer, gas, or paper chromatography—for the separation of compounds.
Various Cameras and Photography Techniques
Alternative light photography helps forensic nurses to identify how much physical damage a patient has sustained, even before physical evidence like bruises manifest themselves on the skin. Meanwhile, UV photography is a valuable technique for identifying cuts, scratches and bite marks found on a victim’s body.
On the other hand, high-speed ballistics photography helps crime scene investigators in recreating bullet holes, shattered panes of glass, and other similar scenarios in order to better understand a case. In fact, identifying and matching bullet trajectories, entrance and exit wounds, and other impact marks is a crucial part of solving a crime that involves guns, bombs, and other similar weapons.
Various Light Sources
Forensic scientists may arrive at a crime scene without any immediately visible evidence to collect. This is where light sources—such as ultraviolet and infrared—may come in handy. Bodily fluids like blood and saliva, wounds, shoe marks, ink stains, latent fingerprints, and even hair and certain types of fibers become visible under different lighting sources. UV and infrared light are preferred by forensic scientists and law enforcement agencies since these don’t corrode or otherwise compromise the quality of the evidence being collected.
There are times when all it takes is a small drop of blood to correctly identify a suspect or even exonerate a wrongfully convicted person. This is what forensics is all about: using science and technology to find the truth and solve crimes.