Closing arguments draw from the prosecutor's opening statement to synthesize the case-in-chief. Cold hard evidence and scientific evaluation is a powerful tool, enabling the prosecutor to counter conjectural defense attacks. While the defense may question the credibility of various witnesses by maintaining that those witnesses have an interest in the outcome of the case, it is often the DNA analyst's unbiased analysis that provides an impartial voice regarding the DNA evidence.

It is important for prosecutors not to oversell the DNA evidence. Careful preparation of the portion of the closing argument concerning the random match probability (or its reciprocal) is essential so that the typing results are confidently and accurately presented. If the case is based on a cold hit, prosecutors should take care not to mention that the hit came from a database of convicted persons. Avoid engaging in improper burden shifting by stating that the defense could have retyped the sample had it wished to do so – unless or after the defense has opened the door.

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