Date of Award
Master of Science (MS)
Paper evidence is commonly encountered in cases of kidnapping, threatening letters, extortion, and bank robbery, and the optimal workflow between latent print processing and DNA collection is of interest to the forensic community. The overall aim of this project was to achieve optimal amounts of DNA for typing without destroying the fingerprint. The first study compared two collection techniques—tape-lifting by Scotch Removable Poster Tape and dry swabbing with FLOQSwabs— using prints deposited in defined locations. Samples were processed for DNA and developed with 1,2-indanedione. The second aim was to determine if visualizing print locations with fingerprint powder prior to DNA collection with fingerprint powder would impact success rates. Each study involved 11 volunteers who were asked to wash and dry their hands, rub their face for 5 seconds and deposit both hand prints on copy paper for 5 seconds. The results showed that tape lifting gave full DNA profiles for all volunteers and after latent print development, with 76% of tape-lifted fingerprint pattern were of value for comparison. In contrast, many partial profiles were seen with the swabbing technique and only 57% of developed swabbed fingerprints were of value for comparison. DNA concentrations ranged from 0.01-0.39 ng/μL for tape-lifting and 0.0009-0.06 ng/μL for swabbing. The fluorescent powder developed prints showed reduced DNA concentrations (0.0007-0.21ng/μL) after tape lifting but still yielded 9 out of 11 DNA profiles. The study indicates that Scotch removable poster tape provides higher DNA yields than the FLOQSwabs and preserves latent prints for development with 1,2-indanedione. Treatment with fluorescent powder does not interfere with DNA typing but impairs subsequent chemical development.
Dalal, Niti, "Optimizing a Method for DNA Recovery while Preserving Latent Prints on Paper" (2018). CUNY Academic Works.