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The Importance of Physical Evidence

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The Importance of Physical Evidence

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What is Physical Evidence?
Physical evidence is any object that can establish that a crime has been committed or can link a crime and its victim or perpetrator. Almost anything can be physical evidence, to list the objects that could be used as physical evidence is impossible. (Saferstein, R. 2009)

Common Types of Physical Evidence
There are several common types of physical evidence that are found at a crime scene and can be used in cases. However, the weight of a given piece of evidence is ultimately decided by a jury. The types of physical evidence include but are not limited to; blood, semen, saliva, documents, hair, fingerprints, paint, fibers, and drugs. The collection of evidence must be thorough enough to include as many pertinent clues as possible, but selective enough not to delay the laboratory. (Saferstein, R. 2009)

Handling Evidence
When handling evidence it must be done to where contamination does not take place. Contamination occurs when the transfer of extraneous matter between the collector and the evidence or multiple pieces of evidence, producing tainted evidence that cannot be used in the subsequent investigation. The use of latex gloves or disposable forceps when touching evidence can prevent contamination. Evidence should not be moved until investigators have

documented its location and appearance in notes, sketches, and photographs. Blood, hairs, fibers, and soil particles should not be removed from garments, weapons, or other articles that bear them. Instead, package the items separately and send the entire object to the laboratory for processing. (Saferstein, R. 2009)

The Examination of Physical Evidence
Physical evidence is usually examined by a forensic scientist for identification or comparison. Identification is the process of determining a substance’s physical or chemical identity, whereas comparison is the process of ascertaining whether two objects have a common origin. The process of...