A comparison of the use of vacuum metal deposition versus cyanoacrylate fuming for visualisation of fingermarks and grab impressions on fabrics

Abstract

Both vacuum metal deposition (VMD) and cyanoacrylate fuming (CAF) are techniques used to visualise latent fingermarks on smooth non-porous surfaces such as plastic and glass. VMD was initially investigated in the 1970s as to its effectiveness for visualising prints on fabrics, but was abandoned when radioactive sulphur dioxide was found to be more effective. However, interest in VMD was resurrected in the 1990s when CAF was also used routinely. We now report on studies to determine whether VMD or CAF is the more effective technique for the detection of marks on fabrics. Four different fabrics, nylon, polyester, polycotton and cotton, were utilised during this study, along with 15 donors who ranged in their age and ability to leave fingermarks, from good to medium to poor, thus reflecting the general population. Once samples were collected they were kept for a determined time (1, 2, 3, 4, 5, 6, 7, 14, 21 or 28 days) and then treated using either the gold and zinc metal VMD process or standard cyanoacrylate fuming. The smoother fabrics, such as nylon, consistently produced greater ridge detail whereas duller fabrics, like cotton tended only to show empty prints and impressions of where the fabric had been touched, rather than any ridge details. The majority of fabrics did however allow the development of touch marks that could be targeted for DNA taping which potentially could lead to a DNA profile. Of the two techniques VMD was around 5 times more effective than CAF, producing a greater amount of ridge detail, palmar flexion creases and target areas on more samples and fabrics.

Visualisation of latent fingermarks on polymer banknotes using copper vacuum metal deposition: A preliminary study

“…These studies applied traditional gold/zinc [12] and silver [13] on dark fabrics to varying degrees of success. Further studies on fabric compared VMD and superglue fuming, which proved VMD to be more effective at developing fingermarks [14]. Despite the recent resurgence in VMD work and the price of VMD chambers dropping substantially over the last decade, very little has emerged recently comparing the efficiency of VMD in developing latent fingermarks on polymer banknotes, and other polymer substrates in general [15][16][17][18][19][20][21].…”

Evaluation of the one-step Lumicyano™ used in the visualisation of fingermarks on fabrics

“…It would be expected that as time passed marks would become less detailed and, hence, less visible, as was observed by Fraser et al in two separate studies [20,30]. Nevertheless, the authors did concede that, on occasion, the trend deviated and more detail was visualised on older samples [20].…”

“…As most studies involving Lumicyano have been conducted on non-or semi-porous substrates, there was an interest to perform several studies on porous materials such as fabrics. In 2013, Fraser et al [30] compared the visualisation of fingermarks on fabrics using vacuum metal deposition (VMD) to cyanoacrylate fuming (CAF). VMD visualised marks better than the CAF method, which is the opposite of what had been previously discovered with non-and semi-porous substrates.…”

Cyanoacrylate fuming method for detection of latent fingermarks: a review

“…Fraser et al (2014) suggested the use of vaccum metal deposition (gold and zinc) over cyanoacrylate fuming method for developing latent fingermarks on different kinds of fabrics such as nylon, polyester, cotton and polycotton as it produced greater ridge detail and more effective than latter one. Dominick and Laing (2011) suggested the use of cyanoacrylate fuming followed by gun blue followed by brilliant yellow 40 dye staining and cyanoacrylate fuming followed by palladium deposition over cyanoacrylate fuming followed by brilliant yellow 40 dye staining, cyanoacrylate fuming followed by gun blue, powder suspension and palladium suspension for developing latent fingermarks on unfired brass cartridge cases.…”