The Duties of a Crime Scene Investigator

What Is A Crime Scene Investigator?


A Crime Scene Investigator or simply CSI is a trained police officer that looks for and analyzes evidences. They are also called as identification officers. They work with the members of the police team but they are more focused on the crime scene itself. Crime scene refers to the location or site in which the incident happened.

CSIs use field kits that contain analysis tools to preserve and document every piece of evidence found at the crime scene. Such evidences will help in processing and solving the crime. CSIs are also responsible in the packaging and transportation of these physical evidences.

What Are The Duties Of A Crime Scene Investigator?


The following are the duties and responsibilities of a crime scene investigator.

Recognizes the scene

A CSI should conduct the initial search upon arrival to the crime scene. During such time, he should develop the strategies and approaches he will use to come up with the useful evidences. The equipment needed should also be determined. The integrity of the crime scene should be maintained also by roping the scene off and marking the areas where the evidences are found.

Documents the crime

This documentation should be forwarded to the officers and law enforcers for further investigation. Sketches, written notes and pictures are all included in the documentation. At this point, the CSI will have the initial interpretation based on the evidences that are currently present.

Collects evidences

After surveying and documenting the crime scene, the CSI should make an effort to search for other evidences that are relevant to the crime. He should communicate to all the people that can testify and provide the missing information. The evidences that are collected should be labelled and preserved properly.

Carries out other legal duties

The responsibilities of an investigator do not end with identifying the suspects of the crime. He should also help the lawyers in preparing criminal proceedings. Reports and evidences should be discussed with the legal officers. At times, investigators also testify in the court. In this regard, CSIs must also be knowledgeable on the laws that are relevant to the crime. This helps them to be able to come up with a clear and justifiable explanation of the meaning of the evidences.

Who Can Become A Crime Scene Investigator?


Police officers who have served for three years can begin their training to become a crime scene investigator. Some departments may require a person to have a specific college degree. Within the training period, they are tasked to do researches, oral exams and written exams as well as course work. Generally, they are trained in all areas of crime scene investigation. However, some may specialize in a specific area like serology, DNA collection and forensic photography.

What Are The Evidences Used By CSIs?


There are two types of evidences present in the crime scene. These are the testimonial evidences and physical evidences. Testimonial evidences are given by those people who have witnessed the incident while physical evidences refer to the items that are left on the scene. These items will prove the facts stated by the witnesses. They will also help in establishing the elements of the crime and identifying the suspect. Physical evidences may include the following:

  • Fingerprints, footwear and bite marks;
  • Weapons like guns or knives and other items like pellets, cartridges and gun powder; and
  • Blood, hair, nails, semen and other body fluids

Crime scene investigators follow an organized approach in processing the crime scene. They are also familiar with the basic relevant state and nation laws that can help them explain the evidences at hand. In general, CSIs are responsible in the collection, preservation and sealing of evidences. They are also responsible in the transportation and documentation of the evidences found in the crime scene.

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