Journal of forensic sciences
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The polyvinyl-alcohol collection method (PVAL) is used in forensic practice to gather topographical information about gunshot residues (GSR) from the hands to decide if the subject has made use of firearms. The results allow a distinction between suicide and homicide. The only inconvenience of PVAL was that the procedure took about 60 min because three layers of liquid PVAL had to be applied and dried. ⋯ The results demonstrate the qualities and advantages of PVAL: topographical distribution of GSR, highest gain of GSR, sampling of all other traces like blood, backspatter etc., and humidity does not reduce the gain. In addition, with the new PVAL 2.0 dislocation of GSR or contamination are excluded. PVAL 2.0 can also be applied on live suspects.