Fingerprint visualization on condoms

Despite emerging DNA techniques, fingerprint evidence remains to be valuable in criminal investigations. Many fingerprinting techniques have been developed over the years; however, previous forensic work has limited research studies geared at the examination of fingerprint visualizing methods for the forensic analysis of condoms. Using common fingerprint powdering techniques, the primary focus of this research project entailed an evaluation of the optimal method of visualizing fingerprints on this specific substrate of vital importance in sexual assault crimes. Tested methods consisted of prolonged cyanoacrylate exposure followed by application of black fingerprint powder, bi-chromatic powder, and phosphorescent powder using the fiberglass brush. Another tested method consisted of cyanoacrylate exposure followed by application of black magnetic powder using the magnetic wand. A novel approach presented in this study is the handling of the “used” condoms prior to treatment. The samples analyzed were placed over large plastic tubes after cyanoacrylate treatment prior to powdering application. This handling procedure proved to be instrumental in attaining quality results. Furthermore, the analytical methodology also evaluated four different time variables after fingerprint deposition to assess the effect of fingerprint aging with respect to the tested powdering techniques. Results demonstrated quality fingerprints can be obtained on simulated –used condoms and that magnetic powder yielded the optimal results overall based on grading criteria for comparison purposes. Furthermore, multi-factor analysis of variance yielded significant effects for condom brand (p < 0.0001), time since deposition (p = 0.0075), and powdering method technique employed (p < 0.0001). The analytical validation of various fingerprint powdering techniques for condom substrate samples can improve and further validate the use of this trace evidence and help establish the availability of fingerprint details that may lead to increased rates of prosecution within the criminal justice system as it relates to sexual assault crimes.