Which of the following is NOT a method for searching an area?

The process of searching an area in the context of fire investigation involves systematic methods to ensure that evidence is thoroughly and effectively gathered. The grid, lane, and loop methods are all recognized techniques used to conduct comprehensive searches. These methods are designed to maximize coverage of an area, allowing investigators to identify clues, debris, or other evidence that could indicate the presence of a fire's origin or cause.

The grid method involves dividing the search area into smaller squares and searching each square methodically to ensure no area is overlooked. The lane method, often utilized in smaller areas, involves dividing the area into lanes and searching each lane in parallel paths. The loop method involves searching in overlapping circular patterns, which can be effective in certain scenarios.

In contrast, the diagonal method, while it can be an effective way to search in some contexts, is not a standard or widely recognized search technique in the realm of fire investigations. As such, it is not included among the established methods that are typically employed for systematic searches. This distinction illustrates why the diagonal method is appropriately identified as not being a recognized method for searching an area in the context of this question.