This article discusses the results from rigorous analysis of some complicating factors regarding the reliability of touch-DNA persistence, including low quality, high variability, and DNA degradation; it provides details on testing for persistence of dry and hot degraded DNA, and the evaluation of whether there is insufficient or degraded DNA.
Research funding by the National Institute of Justice reveals how long DNA is detectable on various surfaces under different conditions. In 2018, the Forensic Technology Working Group at NIJ called for "comprehensive, systematic, well controlled studies that provide foundational knowledge and practical data about 'touch evidence' persistence in the real world." That same year, Dr. Meghan Ramsey's group at the Massachusetts Institute of Technology (MIT) Lincoln Laboratory began quantifying how long touch DNA would persist on certain surfaces under specific conditions. Building on that knowledge, and in collaboration with Dr. Ramsey, scientists at South Dakota State University created predictive models of how DNA degrades on different surfaces under a range of environmental conditions.