Gabriella Annunziato

Pressure sensitive adhesive tape, duct tape, is a thin and flexible material that contains a sticky side for adhesive purposes in which the bond for adhesion is formed due to the application of pressure. Duct tape is commonly used and manipulated in a variety of crimes such as murders, kidnappings, the construction of explosive devices, motor vehicle accidents, the handling and processing of illegal goods/drugs, and sexual assaults. Due to its frequent inclusion in crimes it is generally the subject of forensic evaluation for DNA recovery. DNA can be transferred to duct tape through handling and contact in which an individual comes in contact with the adhesive side of the tape leaving behind epithelial cells. However, DNA recovery rates have been found to be low and often below the minimal amount required for amplification. The reasons for low DNA recovery rates in many situations are still uncertain. There have been studies completed to determine the DNA recovery rates from electrical tape as well as the chemical differences between tape types and effects of time on the rates of recovery of DNA. In this study, blood samples containing known amounts of DNA were applied to the adhesive sides of 6 different types of duct tape, the duct tape was left to dry overnight, and the amount of DNA recovered was determined the following day. We found that duct tape type does affect the recovery of human DNA from duct tape. However, the reasoning for different DNA recovery rates cannot be definitively deduced from the current study. The differences in the physical characteristics among the duct tape types may be reason for the differences in the amount of DNA recovered while the composition of duct tape did not prove to affect the recovery of DNA. Therefore, the study demonstrated that the type of tape DNA is transferred to as well as the differences in adhesives, the tape’s composition, and the tape’s physical characteristics possibly affects the amount of DNA recovered and that time can deter the outcome of a case.