Answer:
1. Line.
2. Zone.
3. Spiral.
Explanation:
In crime scene investigation, individuals who are certified professionals (investigators) in collecting evidence after an unfortunate incident such as murder has occurred use the following strategic investigative methods or techniques;
1. Line method: investigators move from one side of the crime scene to another in a single direction. This method is best used in areas that comprises of obstacles e.g rocks, trees, pillars etc.
2. Zone method: crime area is divided into multiple square areas and each is assigned to an investigator. This method is best used in buildings such as hospital, office, school etc., because these investigators are assigned to each zone of the divided crime area.
3. Spiral method: from the outside or the center of the crime scene, the investigator walks down a circular path and works their way inward or outward.
