Independent Evaluation of Fingerprint Technology Reveals Benefits Over Existing Processes

June 24, 2021 — Speak to fingerprint examiners about a new technology that can develop marks on fired ammunition and most will be skeptical. Some will have previously had their fingers burned, perhaps having invested considerable funds into the purchase of equipment that promised but failed to deliver. The rest will tell you that it’s just plain impossible—many laboratories simply do not process bullet casings for this very reason. However, that has now changed thanks to RECOVER, a unique fingerprint fuming technology capable of revealing “previously difficult or impossible” fingerprints on metallic surfaces.

Figure 1. Fired ammunition casings are loaded into the RECOVER system

Launched in 2019, and now the subject of an independent comparative evaluation conducted by an accredited UK government laboratory, the RECOVER process has been shown to out-perform other techniques, including VMD and cyanoacrylate fuming, on a variety of evidence types exposed to a range of environments.

Jointly developed by foster+freeman, the MoD Defence Science and Technology Laboratory (Dstl), the Home Office Centre for Applied Science and Technology (CAST), and Loughborough University, RECOVER:LFT is a cutting-edge technique that uses an innovative chemical fuming process to develop fingerprints on a range of difficult surfaces including those that have been exposed to extreme heat (discharged bullet casings, for example) and items that have been washed "clean" in an attempt to prevent identification.

Originally designed for deployment in war zones, where it was used to develop fingermarks on bullet casings and bomb fragments, the RECOVER process has now been independently recognized as the superior technique for the development of prints on significant evidence types, including metals exposed to high temperatures and items that have been purposely washed clean (using an acetone solution).

Figure 2. Fingermarks on a fired cartridge are revealed using the RECOVER technique and digitally 'unwrapped'

Figure 3. A fingermark, developed using RECOVER, is clearly visible

No Prints? No Problem

Unlike most existing fingerprint development techniques, the RECOVER process does not require a biological trace to be present to develop an identifiable mark with 3rd-level ridge detail.

Should a trace be present, the RECOVER process will develop the mark in a conventional manner along the ridges of the natural skin oils that are present.

However, if there are no biological traces present (perhaps destroyed by the high flash temperature of a gun being fired), the RECOVER process can reveal equally impressive fingerprints thanks to a unique chemical reaction that occurs on the surface area where skin oils had previously resided.

In fact, the technique is so sensitive that it can even reveal prints on the blade or handle of a knife that has been purposely washed clean and then discarded into a river or lake before being retrieved for examination.

Figure 3. Fingermarks revealed on knife that had been submerged in water for 1-week

Fingerprints or DNA?

In addition to developing "impossible" fingermarks, the RECOVER process offers a further operational benefit by solving the chicken and egg problem of DNA analysis.

Currently, when an item of evidence requires processing by both fingerprint and DNA laboratories there is a tough decision to be made. Swabbing for DNA can interfere with latent print development while many fingerprint development processes can compromise the DNA process and increases the risk of cross-contamination evidence.
However, because the RECOVER process does not require DNA to be present, evidence can safely be swabbed for DNA without fear of destroying the potential to visualize fingermarks.

Must-have Technology

Thanks to its ability to reveal previously "impossible" fingermarks, leading fingerprint laboratories have been quick to adopt the new technology. Manufactured by UK firm Foster+Freeman Ltd., RECOVER instruments have been purchased by key police forces and government agencies worldwide including the UK Defence Science and Technology Laboratory (DSTL) and the United States government, as well as multiple state and county police forces intending to use the technology for cold case review as well as future investigations.

Further information on RECOVER technology:

The Orange County Sheriff's Office Forensics Unit has a new crime fighting tool called RECOVER Latent Fingerprint Technology. The system allows the Forensics Unit to get fingerprints off difficult surfaces.

The RECOVER instrument and process are subject to Patent Application Nos. GB1804040.2 and PCT/GB2018/000040 licensed from the Secretary of State for Defence

Published by Science & Justice Journal, the article A comparative evaluation of the disulfur dinitride process for the visualisation of fingermarks on metal surfaces is an independent evaluation of the disulfur dinitride process that is referred to here as ‘The RECOVER’ process.

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