EMI Standards and Best Practices

Chapter 6 – Evidence Storage

Purpose: Storing evidence in conditions that preserve the forensic integrity and original condition of the item is a key principle of evidence management. Efficient evidence storage operations utilize organization and filing systems in concert with appropriate storage methods and technology to maximize available facility space. Effective evidence storage operations facilitate the location and retrieval of any evidence item in a timely manner. Implementation and adoption of the Evidence Storage standards and practices recommended by the Evidence Management Institute promotes a stable organizational baseline for sustainable evidence management.


Scope: Evidence Storage Standards and Best Practices

Organization System Standards and Best Practices

Storage System and Method Standards and Best Practices


Definitions: Organization System. The overall set of patterns, principles and rules that govern methods and systems used for evidence item filing, storage and retrieval.

Storage Method. Refers to appropriate environmental storage conditions and equipment types utilized to organize and store evidence.

Storage System. Refers to an associated network of storage equipment intended for a single or specific purpose.

Long Term Storage. NIST defines long term storage as any location where evidence may be stored for more than 72 hours.

Temporary Storage. NIST defines temporary storage as any location where evidence may be stored for less than 72 hours.

Chapter VI. Evidence Storage

  1. Evidence Storage Standards
    1. General Evidence Storage Standards
      1. All evidence should be stored in a secure environment that supports the preservation of the item in submitted condition with an unbroken chain of custody.
  1. Evidence Storage Best Practices
    1. Evidence Storage Area Practices
      1. General Issues to Avoid
        1. Stacking packages on top of other packages.
        2. Overstuffing locations
  2. Organization System Standards
    1. Organization System Design
      1. The organization system utilized by an evidence management unit should be based on a logical structure that facilitates the efficient location and retrieval of evidence items in storage.
      2. The organization system utilized by an evidence management unit should minimize wasted storage space.
      3. Rules and principles for the organization system employed should be documented in the evidence management operations manual.
    2. Organization System Benchmark
      1. The optimal benchmark for the efficiency of an organization system is a system:
        1. Where any item documented and stored by the evidence management unit
        2. In any location within the evidence storage area
        3. Can be located, retrieved and subsequently re-filed in under five minutes of entering the evidence storage area
        4. Without additional time required to restore the storage location to original condition
  1. Organization System Best Practices
    1. Organization System Design Testing
      1. To determine organization system design efficiency, it is recommended to test the system using a subject unfamiliar with the system design.
      2. Provide the test subject with a specific item to retrieve and a map of storage locations. Under escort by evidence management unit personnel, time the subject from storage area entry through item location. Compare the timed result to the five minute standard and evaluate.
    2. Storage Location Issues
      1. Using excessive storage locations can decrease the efficiency of the organization system. An organization system that utilizes both location and section designations (such as Drug A, B, C, D) is more susceptible to misfiling evidence than a single sequential location designation.
  2. Storage System and Method Standards
    1. Environmental Conditions for Evidence Storage
      1. The 2013 National Institute of Standards and Technology (NIST) publication The Biological Evidence Preservation Handbook: Best Practices for Evidence Handlers documents environmental storage conditions for evidence storage. NIST establishes the following environmental storage conditions and standards:
        1. Frozen. Temperature is maintained thermostatically at or below –10°C (14°F).
        2. Refrigerated. Temperature is maintained thermostatically between 2°C and 8°C (36°F and 46°F) with less than 25% humidity.
        3. Temperature Controlled. Temperature is maintained thermostatically between 15.5°C and 24°C (60°F to 75°F) with less than 60 % humidity.
        4. Room Temperature. Temperature is equal to the ambient temperature of its surroundings; storage area ma lack temperature and humidity control methods.
      2. Evidence should be stored under suitable environmental conditions to preserve the evidence item in submitted condition. Some evidence items submitted will invariably degrade under storage conditions. It is important to research appropriate storage conditions for each item type.
      3. Temperature controlled environmental conditions should be the default storage condition for most evidence storage. Most manufactured materials and equipment, and this most items, will degrade rapidly if stored under conditions where temperature and humidity are subject to uncontrolled fluctuation.
    2. Common Storage Methods and Equipment
      1. Shelving
        1. Static or fixed shelving
        2. Adjustable shelving
        3. High-density mobile shelving
      2. File Cabinets and High-density Mobile Filing Cabinets
      3. Wall Storage
      4. Safes or Vaults
      5. Cold Storage
        1. Refrigerators
        2. Freezers
      6. Rack Storage
      7. Conveyor Storage
    3. Storage System Capability, Capacity and Selection
      1. Storage systems utilized by the evidence management unit should be capable of storing all existing evidence and accommodate new evidence submission under appropriate conditions as defined by the organization system plan.
      2. Storage system capacity is directly impacted by the effective deposition rate of evidence management unit operations.
      3. Storage systems should be selected based on:
        1. The most efficient method for storing and retrieving evidence
        2. That maximizes storage capacity and eliminates wasted space
        3. Utilizing approved packaging materials for the designated location
        4. Under appropriate
  1. Evidence Management Technology Best Practices
    1. Common Storage Area Functions for Evidence Management
      1. Temperature controlled storage area.
      2. Non-evidentiary property storage area.
      3. Cold case storage.
      4. Cold storage
      5. Hazardous materials or chemical storage area
    2. Special Handling Storage Areas
      1. See Chapter 8: Special Handling Considerations for more information on firearms, currency, narcotics, biological and high-value evidence storage issues.
  2. Reserved
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External References:

National Institute of Standards and Technology. 2013.  The Biological Evidence Preservation Handbook: Best Practices for Evidence Handlers. (NISTIR 7928). Washington DC: U.S. Government Printing Office.

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