Role of the Expert in the Laboratory

Laboratory Previously Involved in the Case

A laboratory previously involved in the case may be requested to provide information regarding:

• The meaning and limitations of any previous test results obtained, including all serological and/or DNA testing and all results reported as inconclusive regardless of whether they were used at the trial or whether evidence still exists for retesting.
• Whether any evidence remains.
• The location and storage history of any remaining evidence.
• The laboratory's policies for the release of evidence to the defendant.
• The laboratory's policy for providing discovery (laboratory case notes and copies of data, or laboratory reports) regarding the disclosure of previous test results. The laboratory may also be requested to serve as a consultant to the attorney(s), judge, or defendant regarding DNA testing.

In a postconviction proceeding, the laboratory will likely be requested by the attorney(s) or ordered by the court to retain and preserve any evidence that remains in the laboratory's possession. The laboratory should locate the evidence and ensure that it is stored in a proper manner to preserve the samples for future DNA testing. Generally, stains, bones, and teeth should be stored dried at room temperature, 4 degrees C, or frozen; liquid samples should be stored frozen; and tissue samples should be stored frozen (preferably at -70 degrees C).

Laboratory as a Consultant

A laboratory may be requested to serve as a consultant to the attorney(s), the defendant, and/or the judge. It is important that expert personnel serve in a fair and unbiased manner as consultants to advise on issues regarding DNA testing in the particular postconviction proceeding, such as:

• The limitations and meaning of test results previously obtained.
• What evidence could and should be tested that would likely yield interpretable results.
• What DNA tests should be considered and what are the limitations and advantages of each test.
• Which DNA testing laboratory should be selected to do the testing.
• The possible results and the meaning of each of those possible results.
• Whether samples from additional individuals are required for the testing.

DNA Testing Laboratory

The DNA testing laboratory, in addition to serving as a consultant to the attorney(s), the defendant, and/or the judge, has an obligation to perform quality DNA tests according to accepted procedures and to interpret and report the results accurately and without bias. The laboratory expert may be required to present the test results and the conclusions derived from the test results in court.

Go to the Next Section: Considerations for Selecting a Laboratory for DNA Testing

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