The effect of electron beam irradiation on forensic evidence. 1. Latent print recovery on porous and non-porous surfaces

The recent use of the postal system as a means of delivering anthrax spores via several contaminated envelopes has led to the selective irradiation of mail. These as yet unsolved attacks and the U.S. Postal Service's decision to irradiate certain types of mail has led to some unexpected complications. The high doses of radiation required to destroy biological agents like anthrax are sufficient to induce damage to other materials present in the envelope. There have been reports of damage to many different items that have been subjected to irradiation, including paper, precious gems, plastic, computer discs, and electronics. However, few studies have examined the effect of such treatments on items of forensic interest. In this paper, the authors focused on the impact of the irradiation process on the ability to visualize latent prints. This experiment involved using several donors, substrates (both porous and non-porous), and visualization reagents. The results indicate that the irradiation process can have a detrimental effect on the success of certain visualization reagents.