Use of gelatin lifters and episcopic coaxial illumination for the recovery and imaging of latent fingermarks from various surfaces

A study was conducted to assess the effectiveness of gelatin lifters as a method of latent fingermark recovery. Such a capability may be important in covert operations where rapid, non-destructive techniques need to be applied. A preliminary trial was conducted to determine the best surface types for fingermark recovery using black gelatin lifts, with the resulting lifted impressions imaged using an optical method referred to as episcopic coaxial illumination (ECI). As expected, it was found that fresh, sebum-rich fingermarks on smooth, nonporous surfaces produced the best results. A more extensive study was then conducted using natural fingermarks from multiple donors and fingermarks aged for periods up to six weeks. Both black and white gelatin lifters were assessed, as well as the impact of reattaching the protective plastic film provided to cover the lifted impressions. The best results were obtained using black lifters applied to nonporous surfaces that contained sebum-rich, relatively fresh impressions (i.e., aged for a short period of time). Lifts that were left uncovered prior to ECI imaging also resulted in higher quality fingermarks. The use of a commercially available ECI accessory was found to be a cost-effective method for the recording of lifted impressions.