How To Prevent Destruction of Evidence at Crime Scene



Upon arriving at a crime scene, experts suggest that you follow a protocol of stages when it comes to examining the area to help prevent destroying evidence. During the early stage of your examination, crime scene investigators cannot assess which type of evidence will contribute in solving the case. Hence, gathering them all for analysis later on will help the progress of the case.

First Level of Search

This will consist the most superficial and basic level of the search. Here, crime scene investigators will try to identify the most efficient search pattern to be used for the environment available at the crime scene. Crime investigators and experts have predetermined search patterns for a given type of crime area. For instance, if its inside an apartment, they'd be using the “zone” search and the “grid” search is done on open areas.

During this level of the search for evidence at a crime scene, investigators use only their eyes as tools for the search. Hence, none of the potential evidence are moved or altered. Investigating officers also come in groups, such that another set of eyes will review the area in case one officer misses a given evidence. 

Second Level of Search

Unlike the first level of search in a crime scene investigation, this level is more thorough. It allows the movement of objects within a crime scene after the original pattern of the crime scene has been documented or photgraphed, provided that it offers only minimal intrusion from the original crime scene setup. Here, you can look through closet doors, underneath home furnitures, or inside drawers. 

For items that investigators conclude to produce significance to the investigation, they will be marked with numbers. Hence, it will mark previously noted evidence and take note of what else could be found in the scene. 

Third Level of Search

Of all levels of search within a crime scene, this one is the most intrusive. Aside from merely opening drawers or closets, you can empty them for a thorough search. Just like with the second level, make sure to mark anything you find that could potentially contribute in the progress of your search. In addition to searching and marking items, this level of your search during crime scene investigation will involve your search for patent or latent prints. Chemicals can also be used to detect any type of fluid that is found on the crime scene, whether it be blood or some other type of bodily fluids. They are collected and later tested on crime laboratories for further evidence.

One of the most crucial elements in the third level of search within a crime scene is having proper documentation for all evidences collected before it is destroyed. To review the search, there are also some other methodologies employed such as final walkthrough or preliminary survey. 

Additional Tips

Whether you are part of the investigating team or a mere onlooker, everyone has a contribution at preserving a crime scene and all present evidence. Onlookers or witnesses are most likely the first ones to arrive at a crime scene. Here's how you can contribute in preserving evidence for the investigators to find later on:

•	Respect barricades and boundaries created by crime scene investigators at an area. This is aimed at preserving evidence.
•	When you are first to arrive at the scene, prevent anyone else from entering a crime scene until crime investigators arrive.
•	When you witness a suspect took off with their vehicle, jot down license plate numbers or vehicle descriptions. 
