CLPEX Chat Board

In the July-August 2008 issue of Evidence Technology magazine, "Getting Out of the Loupe" was co-authored by the Lakewood PD Forensic Identification Supervisor and Latent Print Examiners (Eilers, Patterson, Gallegos), which provided a general overview of our digital image based latent comparison process. We are curious if other agencies are doing something similar and what other variations/processes they may be utilizing for latent comparisons using digital imaging?

Greg Eilers
Forensic Identification Supervisor
Lakewood PD - Colorado

Hi Greg,

Our organisation started in the late 1990's evaluating digital comparator alternatives to traditional photographs and magnifiers. We came up with a prototype which was validated and then a new program written in a different language that was faster and more effective. The latest version of the program has been released but is yet to be validated for our computer system. Keep an eye on this forum for information update.

The experience we have had over the past four years has confirmed that this method for examining digital images of fingerprints is definitely better for both the examiner (OH&S) and for results. The actual set up is not dissimilar to that of an AFIS terminal display except the examination is a manual process whereby the examiner independently plots the features. Each examination captures the quantitative and qualitative data as well as providing an audit trail of how the examination progressed within the ACE method.

Research extensions from the digitial comparator include the Metric tool where an algorithm calculates the linear and angular measurements of the plotted features as a pattern and produces tabulated results showing a summary of analytical information used in the examination. Other research includes distortional variations between inked and latent.

Regards from oz. Les

Thank you for your response and interesting information about the comparison software. We will watch for future posts about its release.

G Eilers