DNA Analysis and Document Examination: The Impact of Each Technique on Respective Analyses

Threatening letters, counterfeit documents, and anonymous notes can commonly be encountered in criminal situations. Such handwritten documents may encourage DNA to transfer from the writer's hands and lower arms when these areas come into contact with the document. As any DNA transferred is likely to be at a low level, sensitive low copy number (LCN) DNA analysis can be employed for testing document exhibits. In this study, we determine locations on the document that are most commonly touched during writing and handling and compare DNA recovery from these sites. We describe the impact of DNA sampling on subsequent document examination techniques including the ESDA^® and likewise the effect of the ESDA^® and two other document examination techniques on subsequent DNA analysis. The findings from this study suggest that DNA results can be obtained through targeted sampling of document evidence, but that care is required when ordering these examination strategies.