Chemical enhancement of soil-based marks on nonporous surfaces followed by gelatin lifting

This study assessed the use of processing techniques (potassium thiocyanate, 2-2-dipyridil, potassium ferrocyanide, ammonium pyrrolidinedithiocarbamate, safranin, magnetic powder) for the enhancement of soil-based marks on nonporous surfaces, followed by gelatin lifting for the recovery of these marks. Other variables in the study included the use of nonporous substrates with varying colors (ceramic tiles, glass, linoleum, plastic bags, leaflets) and different aging periods (1, 7, 14, and 28 days) prior to enhancement and gelatin lifting. A numerical grading system from -1 (deterioration) to 4 (recovery of all fine detail) was adopted to assess the quality of the enhancement achieved.In this study, the two most effective chemical enhancement techniques for soil-based marks on nonporous surfaces were safranin and potassium thiocyanate, specifically on grey linoleum and white ceramic tiles. One-day aging of soil-based marks provided poor results, whereas 28-day aging periods provided superior enhancement. In general, lifting with gelatin lifts provided further improvement on the initial enhancement, by means of contrast and sharpness. However, the use of gelatin lifting sometimes resulted in the deterioration of the original mark. Marks treated with safranin and lifted with white gelatin lifts provided even further improvement through fluorescence examination

Evaluation of Lumicyano cyanoacrylate fuming process for the development of latent fingermarks on plastic carrier bags by means of a pseudo operational comparative trial

There are a number of studies discussing recent developments of a one-step fluorescent cyanoacrylate process. This study is a pseudo operational trial to compare an example of a one-step fluorescent cyanoacrylate product, Lumicyano™, with the two recommended techniques for plastic carrier bags; cyanoacrylate fuming followed by basic yellow 40 (BY40) dyeing and powder suspensions. 100 plastic carrier bags were collected from the place of work and the items were treated as found without any additional fingermark deposition. The bags were split into three and after treatment with the three techniques a comparable number of fingermarks were detected by each technique (average of 300 fingermarks). The items treated with Lumicyano™ were sequentially processed with BY40 and an additional 43 new fingermarks were detected. Lumicyano™ appears to be a suitable technique for the development of fingermarks on plastic carrier bags and it can help save lab space and time as it does not require dyeing or drying procedures. Furthermore, contrary to other one-step cyanoacrylate products, existing cyanoacrylate cabinets do not require any modification for the treatment of articles with Lumicyano™. To date, there is little peer reviewed articles in the literature on trials related to Lumicyano™ and this study aims to contribute to fill this gap

A preliminary investigation into the use of alginates for the lifting and enhancement of fingermarks in blood

Recent studies have reported the use of alginate in the lifting and subsequent enhancement of footwear marks in blood. A study was set up to assess the use of such a method in the treatment of fingermarks in blood on a variety of porous, non-porous and semi-porous surfaces. Other variables included ageing of the fingermarks in blood and the application of chemicals prior to or post-alginate lifting. All different variations were compared to direct chemical treatment of the substrate. The results demonstrated that alginate is not compatible with certain substrates (e.g. glass and tile). On substrates that were compatible with alginate (e.g. fabric and paper), the enhanced fingermarks on the alginate cast and the enhanced fingermarks on the post-alginate substrates appeared, overall, inferior compared to direct chemical enhancement without the use of alginate. A further variation using water-based protein stains directly mixed with the alginate appeared to provide enhancement directly on the substrate as well as simultaneous lifting and enhancing the fingermarks in blood on the alginate cast

A review of one-step fluorescent cyanoacrylate techniques

A review of recent research in the use of one-step fluorescent cyanoacrylate techniques is presented. Advantages and disadvantages of such techniques in comparison to two-step processes are discussed. Further studies and new experimental data are presented to aid this review: three one-step cyanoacrylate products (Lumicyano, PolyCyano UV and PECA Multiband) containing a fluorescent dye were tested to evaluate their effectiveness in developing latent fingermarks on polyethylene bags by means of a pseudo operational trial. The results were compared to the traditional two-step process of cyanoacrylate fuming followed by staining with ethanol-based basic yellow 40 (BY40). The study was conducted using sequential treatments of an initial fuming cycle, a second cycle and finally BY40 staining. LumicyanoTM and PolyCyano UV performed similarly before BY40 staining, with both providing good contrast and visibility under fluorescence. PECA Multiband, however, did not develop as many fingermarks and proved to be problematic for the fuming cabinet. Subsequent BY40 staining of fingermarks developed by all three one-step processes enabled the visualisation of new fingermarks

The effect of cyanoacrylate fuming on subsequent protein stain enhancement of fingermarks in blood

This study investigates the effect of cyanoacrylate (CA) fuming, at atmospheric and vacuum conditions, on subsequent protein stain (acid violet 17) enhancement of fingermarks in blood. Fingermark depletions in blood were deposited on three nonporous surfaces (e.g., plastic bag) and aged for a set period of time (up to 28 days) before enhancement with the water-ethanol-acetic acid and methanol formulations of acid violet 17 (AV17). All trials were carried out in duplicate. One depletion was pre-treated with CA fuming followed by the enhancement technique and the other depletion was treated with only the enhancement technique (control).As expected, atmospheric CA fuming hindered the subsequent enhancement of blood with the AV17 water-ethanol-acetic acid formulation but not the methanol formulation. The same observations were also recorded under vacuum CA fuming conditions. Preliminary work with vacuum metal deposition did not hinder subsequent AV17 protein stain enhancement with either formulation

Water-soaked porous evidence:a comparison of processing methods

This study compared the U.K. Home Office formulation for physical developer (PD) against Oil Red O (ORO) and a modified formulation of physical developer (MPD) that uses Tween 20 instead of Synperonic-N for enhancing fingermarks. Three different donors deposited fingermarks on porous surfaces (white paper, leaflets, and cardboard), with aging periods varying from 7 to 28 days. None of the techniques that were tested provided enhancement of latent fingermarks on leaflets, whereas poor-quality enhancement was observed on cardboard. In contrast, all techniques were more successful on white paper surfaces. The results obtained on white paper suggested that PD and MPD performed similarly, with PD detecting 82.3% of the deposited fingermarks and MPD detecting 86.5% of the deposited fingermarks. PD yielded a higher percentage (38.5%) of fingermarks with fine ridge detail (i.e., those with grade 2 or above) than MPD (35.4%). ORO, however, yielded poor results, enhancing only 4.5% of latent fingermarks, but showed no ridge detail in any of the enhancements (i.e., only showed grade 1 enhancements.

Archaeological sites as national monuments

Paper presented at the Wits History Workshop: Myths, Monuments, Museums; New Premises? 16-18 July, 199

Pseudo-operational trials of Lumicyano solution and Lumicyano powder for the detection of latent fingermarks on various substrates

This study presents pseudo-operational trials comparing a one-step fluorescent cyanoacrylate process with a number of other enhancement techniques on a variety of substrates. This one-step process involves a product, 4% Lumicyano, which is a solution consisting of 4% by weight of a powdered dye (Lumicyano powder) dissolved in a cyanoacrylate-based solution (Lumicyano solution). The cyanoacrylate in the Lumicyano solution may be of a higher quality than that used in the two-step products.One hundred items were collected from the place of work for each trial. Trial 1 involved a comparison of 4% Lumicyano with the conventional two-step cyanoacrylate fuming-dye staining for the detection of latent fingermarks on plastic carrier bags. Trial 2 assessed the quality of the Lumicyano solution (with no powdered dye) but used in a two-step process with basic yellow 40 (BY40). Trial 1, using 4% Lumicyano powder and traditional cyanoacrylate → BY40 detected a similar amount of fingermarks (~295); however, sequential BY40 treatment (i.e., after 4% Lumicyano) detected an additional 30% marks. Trial 2 resulted in the detection of 565 marks after Lumicyano solution → BY40 in comparison to 489 marks after traditional cyanoacrylate fuming and BY40 staining. Trials 3 through 5 compared 4% Lumicyano, 1,2-indanedione-zinc, and ninhydrin on junk mail, magazines, and cardboard used for food or cosmetic packaging; the detection rate was low for all techniques and substrates. Trial 6 on cardboard packaging using 4% Lumicyano, black iron-oxide powder suspension, and magnetic powder also provided a low detection rate. Trial 7, using 4% Lumicyano → BY40, solvent black 3, and iron-oxide powder suspensions on cardboard packaging from a fast food chain, indicated that 4% Lumicyano → BY40 might be a suitable alternative to solvent black 3 and iron-oxide powder suspensions for suspected greasy marks

Regsverteenwoordiging tydens dissiplinêre optredes en arbitrasies — ’n kort oorsig oor die huidige regsposisie

With the recent amendments to the Labour Relations Act 66 of 1995 the question of legal representation was raised again. This article deals with the current legal position and explains the advantages and disadvantages of legal representation during disciplinary action and arbitrations. In conclusion legal representation should always be an option for any party during any disciplinary action. The presiding officer should, however, have a discretion not to allow legal representation if circumstances allow it. Legal representation will definitely enhance and promote just and fair dispute resolution and disciplinary action. Legal practitioners can play a meaningful role in maintaining good labour relations and ensuring fairness between the employer and employee. There is little justification for summarily excluding legal representation

Southern Infrared Proper Motion Survey I: Discovery of New High Proper Motion Stars From First Full Hemisphere Scan

We present the first results from the Southern Infrared Proper Motion Survey. Using 2 Micron All Sky Survey data along with that of the SuperCOSMOS sky survey we have been able to produce the first widefield infrared proper motion survey. Having targeted the survey to identify nearby M, L and T dwarfs we have discovered 72 such new objects with proper motions greater than 0.5''/yr with 10 of these having proper motions in excess of 1''/yr. The most interesting of these objects is SIPS1259-4336 a late M dwarf. We have calculated a trigonometric parallax for this object of $\pi = 276 \pm 41$ milliarcseconds yielding a distance of $3.62\pm0.54$pc. We have also discovered a common proper motion triple system and an object with a common proper motion with LHS 128. The survey completeness is limited by the small epoch differences between many 2MASS and UKI observations. Hence we only recover 22% of Luyten objects with favourable photometry. However the Luyten study is itself unquantifiably incomplete. We discuss the prospect of enhancing the survey volume by reducing the lower proper motion limit.Comment: 20 pages, 11 figures, accepted for publication in Astronomy and Astrophysic