Evidence collection is gathering evidence by one or more people, usually to support a legal claim. Evidence collection may involve interviewing witnesses and others who know facts relevant to a case, photographing and videotaping physical evidence, examining documents and records, or questioning suspects (Bell, 2019). The types of evidence collection involved are physical evidence, such as fingerprints and blood stains, testimonial evidence, and oral testimony from witnesses. Evidence collection involves conducting contextual analysis to collect as much factual information as possible, including searching, collecting, and organizing all data within this scope.
Locard’s Principle
Locard’s principle is a sampling theory that states that all physical evidence moves back and forth between two places with equal probability (Byard, 2022). This means nothing is blocking or filtering between the source of the evidence, its point of origin, and its analysis by experts. Law enforcers apply this theory hoping to catch a criminal who has committed a crime by collecting samples from several locations and then analyzing them for further clues about the suspect’s identity.
The principle was developed by Dr. Edmond Locard and published in France in 1925 (Byard, 2022). The theory explains that every person has within their body either the profile fragment of a fully formed microorganism or at least one specific structure for a particularly known organism. When collecting evidence in an investigative setting, it is the smallest trace evidence from the scene contaminating that area, for instance, by taking fingerprints, bloodstains, or other bodily fluids from the location where they are collected.
Locard’s principle says that some form of contact forever links all materials that come into contact with each other and will retain a trace. This principle is important when searching for clues at crime scenes because much of the evidence can be found on surfaces such as clothing or floors (Byard, 2022). When someone comes in contact with something, they leave traces of their DNA.
The traces can be found in their fingerprint, hair, or blood. For example, in a rape case, the victim can be examined to collect evidence in semen. The victims are advised not to clean themselves immediately after they are attacked because cleaning can wipe out important evidence. Dr. Locard’s the principle provides a sketch of identifying and collecting evidence from a crime scene.
Basic Steps in Evidence Collection
The investigators analyze the nature of each piece of evidence, including when it was created. They later organize the collected data into statements that can be used as support or opposition to the hypothesis. Collecting evidence begins with establishing the most important items and pieces from a crime scene (Bell, 2019). The investigators then take photos and documents of key elements and scenes to be properly analyzed.
The evidence is then properly placed in something secure like a zip bag, envelopes, or a clean tin and closed well to avoid tampering. The bag or envelope carrying the evidence is labeled with the victim’s name, date, and crime scene. The labeling is to avoid mix up or misplacement in the lab. The examiners also write their names and signature on the envelope. The evidence collected is then handed over for transportation to a forensic lab. The person transporting the evidence should protect it from outside exposure to avoid contamination.
Importance of Chain of Custody
Chain of Custody is the principle used to ensure that sample evidence collected from the crime scene remains accurate, consistent, and reliable and maintains integrity (Badiye et al., 2022). Chain of Custody is the documentation and procedures to ensure that an item of evidence is recorded securely at each stage of its collection, transport, treatment, and analysis. Chain of custody is a vital principle of evidence collection, storage, and preservation that must be understood by anyone concerned with the handling of property or data.
The chain of custody is fundamental because it helps maintain the evidence’s integrity (Badiye et al., 2022). The person assigned to handle the sample is expected to protect it from exposure and ensure nobody else can access it. The chain of custody is a lifeline for any investigation or litigation and should be treated cautiously.
Those assigned to handle the evidence should ensure everything is kept. For example, at a murder crime scene, the investigators should put on hand gloves when touching things like the murder weapon to avoid adding their fingerprints to it. The chain can be as s
Order this paper