Collection of Chemical Evidence

Introduction to Chemical Evidence

Chemical evidence can provide vital information to a forensic analysis, helping to link individuals to crime scenes, and suggesting potential methods of crime.
This type of evidence encompasses a wide range of substances, including drugs, explosives, arson-related chemicals and toxic substances.

Identification of chemical evidence involves a keen eye for detail, knowledge of potential substances and an understanding of their likely hiding spots.
Investigators must be prepared to search a variety of areas at a scene, including less obvious places such as drains, soil or dust.
Close collaboration with lab analysts will be crucial in identifying the need for collecting specific chemical evidences.

When dealing with chemical evidence, it is essential to wear appropriate Personal Protective Equipment (PPE) to protect oneself from harmful substances and to preserve the integrity of the evidence.
Common PPE used may include gloves, lab coats and, in some cases, respirators, depending on the chemicals involved.

Evidence should be collected using clean tools to avoid cross-contamination. In the case of liquid evidence, a syringe or pipette could be used.
Packaging is critical in maintaining the evidence. Types of packaging may include sealed plastic containers or bags.
It is important that all containers used for packaging are clearly labelled with relevant details such as the time, date, location of collection, as well as the collector’s details.

The transport of chemical evidence requires careful consideration to prevent contamination and loss of evidence. It should be stored in appropriate containers, and separated depending on the type of evidence.
Storage should take into account the nature of the chemical evidence. Many substances may require refrigerated storage to prevent chemical change or decomposition.
Chain of custody must be maintained at every step of the evidence collection, storage and transport, to ensure the integrity of the forensic process.

Collecting chemical evidence in a forensic context requires knowledge, attention to detail, and careful consideration of safety measures.
The integrity of collected chemical evidence can directly impact the results of forensic analysis and subsequent conclusions drawn in the investigation.
Therefore, every step from initial identification to transport and storage of this evidence plays a critical role in the forensic investigation process.