By Georgette M, Hannah & Emily (absent)

What is it? Biological Evidence includes blood of a human or animal, fingernail scrapings, saliva, urine, hair, fibres from clothing, teeth, bone and skin tissue. These are collected from a victim and are used for identifying and characterising genetic factors such as DNA. However, these samples will not count as Biological Evidence when someone is being tested for drugs, poisoning or alcohol.

To collect this information, the evidence can be swabbed with wet cotton wool or even using sticky tape. The evidence will then be identified (once it is collected) to help with the investigation.

What information can it give a scientist? Biological Evidence can identify potential suspects and associate suspects or victims to a crime scene or to one another.

Give an example for one type of insect and how it can identify how long the victim has been dead Insects can help to identify how long people have been dead, because there are different bugs that show up on a decomposing body in different stages. For example, Necrophagous bugs will show up almost immediately after death and begin to pick apart the body. These bugs aid in the breaking down and decomposing of dead bodies. They are drawn to the body by the strong smell of decomposition.

Bow flies begin to invade bodies within minutes of death, and flesh flies will follow soon after. Predatory and parasitic insects arrive to feed on maggot and beetle larvae. As the body dries, hide beetles arrive as well as clothes moths to clean up whatever remains. An entomologist can identify how long the body has been decomposing by what types of bugs are present. Also a corpse can be identified by the level of decomposition seen and the strength of the decomposition smell. These are all tools that aid and entomologist in Time of Death (T.O.D.).