DNA profiling provides strong evidence of the probability that a person was presence or absent at a crime scene. Courts virtually universally accept the validity of DNA evidence. Nevertheless, problems may exist with the foundation for the admission of such evidence because of inadequate laboratory procedures or because the statistical information is flawed. In addition, it should always be remembered that DNA testing does not prove conclusively that a particular person committed a crime. The basis of DNA testing is to indicate the probability that a person with the defendant's genetic makeup committed a crime. Because DNA evidence may aid both prosecutors and defendants, an issue arises as to the duty to preserve DNA-related evidence over a number of years. No universal rule of preservation exists; both courts and legislatures should address this issue. Footnotes