An investigation into the enhancement of fingermarks in blood on fruit and vegetables

Abstract

A number of studies have reported the successful enhancement of latent fingermarks on fruit and vegetables. A study was set up to identify the most effective technique for the enhancement of fingermarks in blood on various fruit and vegetables. The enhancement techniques targeted different components in blood and consisted of protein stains (e.g. acid black 1), peroxidase reagents (e.g. leuco crystal violet) and amino acid stains (e.g. ninhydrin). Different variables such as the ageing periods of the marks and a diminishing series were employed to assess the suitability and sensitivity of the enhancement techniques. Overall, the use of different protein stains appeared to be the most effective techniques for the enhancement of fingermarks in blood on fruit and vegetables. In addition, the aubergine and cucumber skins appeared to be the most responsive surface to the different chemical techniques during enhancement. On the contrary, little or no enhancement was achieved for fingermarks in blood on the nectarine fruit.

Electrochromic visualization of latent fingermarks deposited on nonconductive surfaces

“…1 In some cases, fingermarks bear blood, paint, foodstuffs or similar substances that tend to be visible. 2 However, in most circumstances, one can only obtain invisible fingermarks, which are referred to as latent fingermarks that are composed of dried or spoiled sebaceous sweat trail. 3 Extending the capability to obtain fingermarks by any means possible is of great importance.…”

Multi-Informative and Specific Detection of Blood in Fingermarks via MALDI-MS Based Strategies

“…Although the strips are white and as such already provide good contrast for patent marks, they are also inherently fluorescent, allowing easy visualisation of faint, poorly visible marks [137]. While the Home Office provides extensive recommendations regarding operational workflows, deposition surfaces and suitable enhancement techniques for blood fingermarks in their fingerprint source book [140] and the fingermark visualisation manual [36], studies have also been undertaken elsewhere regarding the recovery of blood fingermarks from fruit and vegetables, and here protein dyes have been deemed the most successful [141]. Several studies have also evaluated the effect of haem-reactive tests and protein-dyes on the success and sensitivity of DNA recovery and analysis, for example demonstrating a reduction in yield by a factor between 2 and 12 [129], especially if the process requires a de-staining step.…”