The benefits of using transparent polyvinylsiloxane for recovery of developed fingerprints on challenging surfaces
This article was originally published in the November/December 2005 edition of Evidence Technology magazine.. By Detective Donald J. Frost II.
Every professional working in law enforcement understands the value of good fingerprint evidence in supporting the investigation of a criminal case. It can assist greatly in the development of a suspect who is possibly associated with the incident and ultimately the arrest and conviction of the actual perpetrator. Good fingerprint evidence can often be the difference between two extremes: getting a confession and conviction—or going through a lengthy and sometimes risky trial based on less-definitive evidence such as witness testimony and other circumstantial evidence. Or even worse, no arrest and no case at all.
A print can often look “good” at the crime scene—or on a piece of evidence back at the laboratory prior to processing—but it might turn out to be almost useless by the time it is developed, recovered, and examined by the latentprint examiner.
Many examiners have been frustrated by the absence of minutia points (unique characteristics in the ridge detail of the print) caused by the improper recovery of a print submitted for comparison. One or two points of comparison that are lost in the recovery of the print can be the difference between a latent print being positively identified as the suspect’s print or an “inconclusive” comparison that makes it useless for the prosecution (and conversely beneficial for the defense) in court. That is why proper recovery is imperative.