Written by: Rishitha Boddu

In recent years, criminal investigation shows have risen to popularity — some well known ones being CSI, NCIS, Criminal Minds, and the classic Sherlock. Even novels such as Nancy Drew, Agatha Christie’s, and of course, Sherlock have been fan favorites, but what is the reality of solving crime? Not everything you see on TV is accurate; however, as technology progresses, fighting crime has also taken on a futuristic look. 

What is Forensics Science?

Forensics science is a crucial part of the justice system that combines law and science into one field. Their job is quite different from crime investigators and coroners. Police detectives, criminal investigators, and FBI agents collect evidence, interview witnesses, and suspects to piece together what went down in a crime. However, criminals are rarely caught without the work of forensics scientists.  Forensics scientists analyze crime scenes by testing samples of fingerprints, blood, paint chips, tire tracks,  hair, and more. This article will review just some of the numerous modern technologies and techniques used in forensics today.

Alternative Light Photography

Alternative light photography is a technology that allows nurses to see physical damage that a patient has suffered even before the symptoms are visible on the skin. Special cameras use blue and orange light to highlight the presence of bruises underneath the upper layers of skin. Different types of light can be used in different scenarios depending on what a professional needs. For example, ultraviolet rays are used to uncover bruises and bite marks, while infrared light enhances blood stains on dark or patterned clothing. In order for these lights to work, forensics technicians study a phenomenon called fluorescence. Fluorescence occurs when light of a certain color and frequency hits an object, causing it to reflect a light of a different color and frequency. Technicians use this knowledge to their advantage to design proper filters for their alternative light source technology to properly see these objects.

Drug Testing

During certain cases, forensic scientists will be required to identify unknown substances. These substances could be in powder, liquid (including stains), or pill form, and it is up to the team to perform the proper testing and present their findings. There are two main types of tests — presumptive and confirmatory. Presumptive tests can help forensic chemists identify what type of substance they are dealing with, but confirmatory tests are needed to identify the specific substance, hence their respective names. 

Color tests are the most common form of presumptive tests; these tests expose the unknown substance to a mixture of chemicals and decide properties of the substance based on the color the solution changes to. There are many different types of color tests — each containing different chemical mixtures and evoking different reactions from substances. Another common type of drug test is the ultraviolet spectrophotometry when substances are analyzed in the presence of ultraviolet and infrared light. 

A method that tends to be more specific in its identification amongst the confirmatory tests is the microcrystalline test. A drop of the unknown substance and a reagent is added to a slide and observed under a polarized light microscope. Each type of drug crystallizes in a distinct way, allowing a  scientist to discern them from each other. 

The final drug test that this article covers is gas chromatography and mass spectrometry. A small amount of substance gets inserted into the gas chromatograph where molecules move at different speeds in alliance with their density. The second step is to send the substance through the mass spectrometer where an electron beam will hit it and cause it to burst apart. Because each specific substance breaks in an unmistakable way, scientists can confirm their hypotheses from previous presumptive tests. 

Fingerprinting

Fingerprinting, known formally as dactyloscopy, is a well-known responsibility of forensics scientists. Interestingly, fingerprints are even more unique to a person than their DNA. Even identical twins who share the same exact genetic code won’t have identical fingerprints, so fingerprinting is a valuable tool during crime investigations. Fingerprints are made up of various patterns including loops, whorls, and arches.

Fingerprints can be taken from a person directly or retrieved as evidence from a crime scene.  There are two types of fingerprints that can be taken from a crime scene — visible prints and latent prints. Visible prints will have been imprinted on an impressionable surface such as blood or clay whereas latent prints are made when sweat, oil, or other liquid substances that humans secrete are transferred on a surface and form the structure of the original fingerprint. Latent prints aren’t actually visible to the naked eyes and have to be observed under lasers or dark powder. 

Before modern technology was invented, people would have to clean their fingers with alcohol, thoroughly dry them, cover their fingers in ink, and do a rolled fingerprint as well as a flat finger print on a card. With modern technology, people can just place their fingers on a digital scanner for a few seconds and the machine converts the print into digital data patterns. The patterns are stored in a database alongside information about other prints, and this data can be compared to fingerprints collected from a crime scene to determine the culprit.

Conclusion

Forensics is such a broad field and there are many different technologies, techniques, and specialized occupations involved in allowing justice to prevail. These are just some of the many different scientific principles and tech that has been studied to be applied to real crime investigations. Forensics is an extremely important field within law and justice and it proves just how powerful STEM can be in the real world.

References and Sources 

admin. “10 Modern Forensic Technologies Used Today – Forensics Colleges.” Forensics Colleges, 2013, www.forensicscolleges.com/blog/resources/10-modern-forensic-science-technologies. Accessed 2 Feb. 2021.

Richards, Clair. “Alternative Light Source Photography.” Pathology, vol. 47, 2015, pp. S23–S24, www.sciencedirect.com/science/article/abs/pii/S0031302516302288, 10.1097/01.pat.0000461398.61037.82. Accessed 2 Feb. 2021.

Penven, Don. “Crime Scenes and Alternate Light Sources.” Crime-Scene-Investigator.net, 2013, www.crime-scene-investigator.net/alternatelightsources.html. Accessed 2 Feb. 2021.

https://www.howstuffworks.com. “How Fingerprinting Works.” HowStuffWorks, 24 Mar. 2008, science.howstuffworks.com/fingerprinting.htm. Accessed 2 Feb. 2021.

“Forensic Science Technology Tools | ATA Scientific.” ATA Scientific, 16 Jan. 2020, www.atascientific.com.au/technologies-forensic-sciences/. Accessed 2 Feb. 2021.

https://www.howstuffworks.com. “How Forensic Lab Techniques Work.” HowStuffWorks, 9 June 2008, science.howstuffworks.com/forensic-lab-technique.htm#pt2. Accessed 2 Feb. 2021.

https://www.howstuffworks.com/about-jonathan-strickland.htm. “How Computer Forensics Works.” HowStuffWorks, 25 Feb. 2008, computer.howstuffworks.com/computer-forensic.htm. Accessed 2 Feb. 2021.

“Forensic Science.” Justice.gov, 6 June 2018, www.justice.gov/olp/forensic-science#:~:text=Forensic%20science%20is%20a%20critical,an%20innocent%20person%20from%20suspicion. Accessed 2 Feb. 2021.

“Fire Investigation – the Forensics Library.” Aboutforensics.co.uk, 2021, aboutforensics.co.uk/fire-investigation/. Accessed 2 Feb. 2021.