A Preliminary Study of Developing Latent Fingerprints on Metal by Vacuum Metal Deposition

Vacuum metal deposition(VMD)technology has been applied to fingerprint development for more than 50 years. It is an ideal tool to develop fingerprints on many difficult substrates. However,there are few VMD studies on metal as a difficult substrates field. In response to this problem,this article selects four common metals such as brass,red copper,stainless steel and aluminum foil,as the inspection materials. By comparing the appearance effects of gold-zinc,silver-zinc,and silver VMD on metal substrates,the article explores the best VMD scheme on the metal substrates and expands the application in the field of forensic science. Experimental results show that on brass,red copper and stainless steel,silver-zinc VMD and silver VMD have similar effects and are better than traditional gold-zinc VMD,while traditional gold-zinc VMD has more advantages on aluminum foil.