The phrase brings to mind images of people dressed in white protective clothing and re-breathers, white or blue yellow banded booties and rubber gloves. There are two people or are key to have a successful crime scene search, they are the Team-leader and Perimeter guard, or checkpoint guard.
The team-leader is the one person who will coordinate the entire search. If the team leader is not in place and not doing the job well, the proper tracking of who did what and what evidence was collected where may not be properly tracked.
This proper tracking is what we call the Chain of Command. This one act alone can cause all the evidence to be thrown out of court if the chain of command cannot be properly traced from discovery and collection, to processing to presentation in court.
The Perimeter guard is responsible to tracking who goes into the crime scene. This officer records what time the person goes in and what time they exit. They will also record the reason for entering: i.e. evidence collection or scene walk through.