Typical scenarios within this site’s subject: questions to ask, materials to prepare and points that can be examined.
Typical scenarios
If a brown fabric stain gives a positive presumptive reaction, a retelling may describe it as human blood. Screening and identifying biological material address different questions. Even a subsequently obtained DNA profile cannot automatically be attributed to blood without an appropriate examination of the stain.
Typical scenarios
If recalculation raises the tree-pollen percentage in a sediment report, it may be described as vegetation change. Yet spores or aquatic plants may have been excluded from the pollen sum. Restore raw counts, inclusion categories and calculation rules for every layer before interpreting the pattern.
Typical scenarios
If pale elongated objects appear in grain residue after warehouse cleaning, their overall appearance may suggest pest larvae. Seed coats and sack fibres may also occur there. Preserve whole objects and record their separate discovery locations before sieving the mixture.
Typical scenarios
If a dark deposit appears on a book binding after archive boxes are moved, a photograph may prompt someone to call it mould. Its earlier presence and any wiping remain uncertain. Reviewing the material requires the object and a record of where it was found.
Typical scenarios
If foreign fragments appear when packaging is opened, resemblance to plant material alone does not establish their nature or origin. Comparative examination may require the actual objects and information about their discovery.
Typical scenarios
If isolated hairs raise a dispute about a fur or textile product’s composition, distinguish the product material from incidental surface inclusions. A hair may be structural or transferred during storage, use or examination. A few different particles do not establish the composition of the whole base.
