Even those with only the slightest bit of knowledge of criminal justice are most likely quite familiar with crime scene investigations. The idea of investigators combing over the scene of the crime for evidence is a scene that we have seen time and time again on television and in the movies, from CSI to Sherlock Holmes. And it’s with good reason – crime scene investigation is a crucial part of the criminal justice system and can make or break a case.
In a crime scene investigation, investigators are tasked with documenting the conditions of a location as they collect evidence that can be used to piece together the story of what happened and who was involved. This process can entail a variety of things, from collecting dried blood from a countertop to searching a room for any weapons or illegal substances. Through it all, crime scene investigators must also take caution not to contaminate any of the evidence by altering any part of the environment (by leaving their own fingerprints or moving things around in the room).
The process begins when police officers or detectives on the scene put a call out for the CSI unit. Once they arrive, an initial walk-through is done to develop a basic idea of what the crime has entailed and what elements will be involved in the case. Next, photographs are taken, sketches are made, and videos are shot. These findings can then be used for further analysis.
At this point, the crime scene investigator begins to collect all potential evidence, tagging and logging items while packaging them so that they will stay intact while being sent to the crime lab for further investigation. Once in the lab, all collected evidence is processed through a variety of tests. This process is known as forensic science.
Some branches of forensic science include:
Forensic DNA analysis – analysts examine DNA samples found at the crime scene. This study can be utilized in paternity/maternity testing or rape investigation.
Forensic toxicology – a human body is tested for drugs and poisons, giving CSIs a better understanding of what may have been the cause of death.
Forensic pathology – the fields of medicine and pathology are used to determine the cause of death or injury of individuals linked to the crime scene.
While not every crime scene investigator is a forensic scientist, many CSIs are, and all of these professionals should have some good understanding of the forensic process. When completed, all test results are then sent to the case’s lead detective.
Crime scene investigation is a painstakingly detailed process, but allows criminal justice professionals to gain a better understanding of the circumstances surrounding crime and can greatly affect a case.