A Limited Validation and Comparison of 1,2-Indanedione and ThermaNin for Latent Print Development on Thermal Paper.

As part of a validation study conducted for the Illinois State Police, two processing techniques (1,2-indanedione and ThermaNin) for visualizing latent prints on thermal paper underwent performance checks prior to their inclusion in the Illinois State Police Latent Prints Procedures Manual. Five participants deposited fingerprints on six types of thermal papers, which were then cut in half lengthwise. Each half was then processed by one of the two techniques. The ages of the sample latent prints were varied as well as the processing times. Preserved latent print detail was evaluated by 10 experienced latent print examiners, who judged the samples for the presence or absence of latent print detail and the quality of any detail produced. In addition, the examiners judged whether prints were suitable for comparison and were asked which processing method was preferred. Both 1,2-indanedione and ThermaNin were productive on sample latent prints, with ridge detail developed on 99.2% and 95% of the samples, respectively. Additional examination of samples meant to imitate casework also showed success. [ABSTRACT FROM AUTHOR]