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Forensic Science: An Overview

Written by: Mary Elgayar

Edited by: Hafsah Faizan and Nadine Grant

What is Forensic Science?

Forensic Science is the technique of using scientific methods to solve crimes. Forensic science includes all three of the main sciences: physics, chemistry, and biology. It is a crucial part of the criminal justice system in the United States. The advancement of forensic science has been used to uncover mysteries, solve crimes, and convict/exonerate suspects of crime for centuries.


The Process


Let’s say a crime takes place at a certain location, and there is a suspected perpetrator(s) and victim(s). When the crime is committed, biological material is transferred between the victim, the crime scene, the perpetrator, and the weapon. Forensic science can prove the existence of a crime in three main steps: first, through examination of physical evidence, then the administration of scientific tests and interpretation data, and finally, clear and concise results for a truthful testimony.

Chemistry and Forensic Science

Forensic Science uses chemistry and technological equipment to collect evidence surrounding crimes. One example of this is fingerprinting. In this process, the scientist will analyze primary chemicals, such as iodine, silver nitrate, cyanoacrylate, and ninhydrin to reveal and gather fingerprints. Another example of this is in the use of blood evidence. A scientist can use chemicals such as fluorescein and luminol, which cause a chemical reaction that can reveal blood stains and smears.

Biology and Forensic Science


When dealing with crimes, there are several types of biological evidence that could be left at a crime scene and could point to the innocence or guilt of suspects.

These include: blood, semen, saliva (e.g. on cigarettes), vaginal secretions, fecal material, hair, urine, and bone. No two human beings have the same nuclear DNA type (with the exception of identical twins). Typically, a nuclear DNA match between a crime scene sample and an individual would be exceedingly rare if the individual was not the true source of the crime scene sample. Thus, forensic scientists (or forensic biologists) would need to excel in DNA analysis.

Physics and Forensic Science


Many fundamental physics principles are applied in forensic science, which includes Newton’s laws, thermodynamics, and friction. However, Thomas Bohan, founder and CEO of MTC Forensics, a technical forensics consulting business based in Maine, stated that “sometimes the application of these requires some subtlety.” Boston State University professor Richard Reimann often gets called to testify in legal cases due to his expertise in physics. On one occasion, Reimann wrote to a local public defender explaining how to distinguish between injuries from shaking a baby and injuries from a head impact. Shaking is generally assumed when the retina has hemorrhaged, “but the medical community needs to look beyond that. If it was shaking, other organs would also be damaged,” he says. These pieces of information have a huge impact on the final court decision.


Forensic science may be a very complex study, particularly in the areas of DNA and trace evidence. However, the study of forensic science is grounded in fundamental concepts and techniques that are gathered from natural sciences. In particular, the study of forensic science involves a multi-disciplinary approach that covers everything from biological methods to analytical chemistry techniques, and is a great area of study for those willing and able to dive into the depths of law as well as science.




Students for STEM is a 501(c)3 certified student nonprofit organization composed of high school and college students. Students for STEM works to educate students and provide students with resources and opportunities in STEM.

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