Determine extent scene already protected. Obtain information from persons who have knowledge of scene's original condition. Keep unauthorized personnel out. Unnecessary law enforcement. Sometimes the biggest problem at crime scenes with unauthorized personnel is with law enforcement.
Issue subpoenas to all who enter.
Log in and out all who come to the scene. Photograph all who enter. The preliminary survey is the stage of the crime scene search in which the basic foundation for management, organization, and logistics is developed to suit the needs of a particular crime scene. Essentially it is a cautious walk through the scene to determine what must be done. Determine manpower and special equipment needs.