If you have ever watched a TV show like CSI, you might have a basic idea of how a crime scene is investigated. In these shows, a crime scene investigator is seen collecting evidence and blood samples. But do these shows depict the exact process of forensic investigation?
The process of investigating a crime scene is long and arduous that involves carefully documenting the complete condition of the scene and the collecting all possible physical evidence that could help in the conviction of the perpetrator. However, every crime scene is different which means an investigator needs to approach the scene accordingly. There are numerous ways and procedures used by investigators to perform a successful crime scene investigation. But whatever the scenario may be, there are certain steps that every crime scene investigator generally utilize. Here are the basic steps employed by a CSI in order to conduct a successful and efficient crime scene investigation. Depending on the condition of the scene and nature of the crime, these steps can be conducted in a different order, combined or even skipped altogether.
1. Approach the Scene
The process of investigation begins the moment CSI unit receives a call from the police officers or detectives and they reach the scene. The main area of the disturbance, i.e. the focal point of the crime is observed to make a mental note of what the CSI sees, hears and smells. At this moment, the investigating officer needs to draw a radius of the focal point in which all the relevant physical evidence may be present. It is at this point that the investigator gets hold of hazardous materials or weapons and identifies the potential areas of ingress and egress of the criminal.
2. Secure the Scene
Often the first responders cause many disruptions at the scene which can disturb potential physical evidence. To prevent this, ingress and egress to the area must be controlled immediately. For this purpose, the scene is generally protected using yellow crime scene tape or rope and cones. After this, to keep a track of the people entering and exiting the scene, a common entrance is established and all people who enter and leave the area are documented.
3. Conduct Preliminary Survey
Now, the CSI takes a walk around the exterior of the structure to identify potential evidence. It is at this point that factors like open windows, damaged doors, ladders, etc are to be taken into consideration. These factors will help in establishing how the predator entered the structure or from where he left. After this, the investigator will conduct a visual survey of the actual scene location and gather as many evidence as possible. The scene is to be recorded with the help of written notes, photographs or even video graphs.
4. Consider Physical Evidence
After considering what happened at the scene, the investigating team will think about what type of evidence should be present. The exact point where the shooting occurred, the position of a gunshot on the victim’s body, traces of blood, signs of a struggle, and visible footprints- all need to be taken into account. Detailed documentation of the scene is prepared with the help of digital and video cameras or a 3-D scanner. In addition to photographs and written notes, sometimes sketches and diagrams are also created. All the collected pieces of evidence are then carefully packaged and preserved. It is necessary to use the right type of containers for carrying all evidence because some items can get contaminated during this process. The objects with blood stains or other physiological fluids should never be packed in plastic bags.
5. Perform a Final Survey & Release the Crime Scene
Once all the potential evidence is carefully gathered, the investigating team needs to take a final walk around the scene to make sure that no important clue or potential evidence is left ignored. After this, the lead investigator or other authorized persons may release the crime scene. However, it’s crucial to make sure that every important piece of information is secured before regaining access because once released some evidence will no longer be available.