Let's look through the basic processes that underlie crime investigation. What we see in the show is just a replica of what is actually happening with the real criminal investigations but there is more to it. This will not only solve problems through logic.
Let's go behind the scenes of how the real process of introducing the culprit.
The first stage is to investigate crimes when investigators arrived and secured a spot. Expert uses different software to analyse the investigation case in great detail. Many companies such as Cognitech which provide real-time image and video processing and analysis software tools to analyse the investigation correctly.
Nothing was touched. What investigators do is the formulation of possible theories about the actual occurrence and speculation and predictions about it.
Typically, securing an investigator if something has been removed, altered, or modified before he arrived. The first step is to conduct an initial inspection of the premises.
The next step is to document the scene through pictures, videos and sketches. investigators saw to it that every angle has been documented for analysis.
No one touches the creatures still during this process. The next step is to get a real touch of anything that could be used as evidence.
Investigators are now touching, collect and document specimen that is of relevance and is estimated to have a relationship with evil.
This is where the investigator tags, logs, and pack all available evidence needed for logical analysis.
This level also allows investigators to make its way to the scene that does not leave behind the specimen. Everything had to be closed for its minute details.