Please discuss the first and greatest priority of the first officer on a sce

 
Please discuss the first and greatest priority of the first officer on a scene.
Then, please discuss their role in documenting evidence and how they might document the information observed.
Additionally, please discuss the need for the first officer to document certain evidence in both, their notes and their case reports.
Finally, please discuss the steps for interviewing victims, witnesses and suspects and how that information should be documented both, in notes and in official reports.