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Principles of Forensic DNA for Officers of the Court

Sample Selection

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National Institute of Justice (NIJ) (see reuse policy).

Caution should be exercised to select samples for testing that provide the greatest likelihood of meaningful results for a particular case. It may be necessary to consider previously collected evidence samples to determine if:

  • Other relevant evidence samples exist that could be tested.
  • Samples exist containing biological material that was previously undetected or not evaluated by the laboratory.
  • Samples have been retained that were unsuitable for testing with previous techniques but may provide probative results with current technology.

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