Fingermark detection on non-porous and semi-porous surfaces using YVO4:Er,Yb luminescent upconverting particles

This article describes the use of an anti-Stokes luminescent material (upconverter), yttrium vanadate doped with ytterbium and erbium (YVO(4):Er,Yb), for the development of latent fingermarks on a range of non-porous surfaces. Anti-Stokes luminescent materials emit light at shorter wavelengths than the excitation wavelength. This property is unusual in both natural and artificial materials commonly found as exhibits in forensic science casework. As a result, fingermark detection techniques based on anti-Stokes luminescence are potentially extremely sensitive and selective. Latent fingermarks on non-luminescent and inherently luminescent substrates, including Australian polymer banknotes (a well-known 'difficult' surface), were developed with YVO(4):Er,Yb by dry powder and wet powder techniques. The effectiveness of YVO(4):Er,Yb for fingermark detection was compared with that of cyanoacrylate fuming and of sodium yttrium tetrafluoride doped with ytterbium and erbium (NaYF(4):Er,Yb). The results illustrate some benefit of luminescent up-converting phosphors over traditional luminescence techniques for the detection of latent fingermarks.     

Performance Standards and Evaluation

The benefits of performance monitoring for public services are identified as greater transparency of objectives and accountability for results. This article considers recent experience in developing standards to evaluate efficiency and effectiveness of public services. In broad terms this is being done through performance information which is a much more encompassing concept than standards or indicators. Such information is an element of an accountability framework that provides greater management autonomy and flexibility and extends to the private sector which is increasingly providing, or involved with the provision of, public services.     

The drug trade in Southern Africa

Introductory Address by Dr. AM Omar MP, Minister of Justice, at the South African Institute of International Affairs’ Workshop on ‘The Drug Trade in Southern Africa’, 5 June 1997, University of the Witwatersrand, Johannesburg.     

Fluorescent TiO2 powders prepared using a new perylene diimide dye: applications in latent fingermark detection

A new, highly fluorescent dye was synthesised using oleylamine combined with a perylene dianhydride compound. The new dye was characterised by 1H NMR, UV-vis spectroscopy and fluorescence spectroscopy as well as quantum yield. The dye was absorbed onto titanium dioxide nanoparticles for use as a fingerprint detection powder. The new fluorescent powder was applied to latent fingermarks deposited onto different non-porous surfaces and compared with commercial fluorescent powders. The powder exhibits strong fluorescence at 650-700 nm under excitation at 505 nm. On glass surfaces, the new powder gave images showing tertiary-level detail of the fingermark ridges with almost no background development. Compared with current magnetic fluorescent powders, the new powder was slightly weaker in fluorescence intensity but produced significantly less background development, resulting in good contrast between the fingermark and the substrate.     

Plays,Performances and Power Struggles – Examining Copyright's ‘Integrity’ in the Field of Theatre

This article explores the notion of ‘integrity’ under copyright law by analysing examples of 'integrity‐based objections' in the field of theatre. These objections typically involve playwrights objecting to changes being made to their copyright works by other parties, such as directors and actors. This analysis is deepened by the use of two concepts from the field of art theory – ‘aura’, as put forward by Walter Benjamin, and ‘trajectory’, as outlined by Bruno Latour and Adam Lowe. Finally, to shed further light on the issues raised, the work of Pierre Bourdieu is used to present new empirical research recently undertaken by the author in the field of UK theatre. This research demonstrates that ‘power struggles’ are a common feature of theatrical collaboration; that copyright is deeply implicated in the way such power struggles are conceived; and moreover, that resolving these power struggles successfully – including taking account of ‘integrity‐based objections’ – is crucial to theatrical practice.     

Fingermark detection on non-porous and semi-porous surfaces using NaYF4:Er,Yb up-converter particles

This article describes the first use of an anti-Stokes material, or up-converter, for the development of latent fingermarks on a range of non-porous surfaces. Anti-Stokes materials can absorb long-wavelength light and emit light at a shorter wavelength. This property is unusual in both natural and artificial materials and so fingermark detection techniques based on anti-Stokes luminescence are potentially sensitive and selective. Latent fingermarks on luminescent and non-luminescent substrates, including Australian polymer banknotes (a well-known 'difficult' surface), were developed with sodium yttrium tetrafluoride doped with erbium and ytterbium (NaYF(4):Er,Yb) by dry powder, wet powder, and cyanoacrylate staining techniques. This study illustrates the potential of up-converter phosphors for the detection of latent fingermarks.     

Methods for the enhancement of fingermarks in blood

Fingermarks formed in or by blood often require specific development techniques. This review examines techniques and materials that may be used to enhance and record fingermarks deposited in blood or fingermarks generated by blood-contaminated papillary ridges. A large number of techniques are presented here and are discussed from a chemical as well as practical perspective. It is concluded that an optimized sequence of techniques targeting both latent (non-bloody) and bloody fingermarks must be applied to detect and enhance the maximum number of marks, and therefore optimize the information content from exhibits that may bear marks in blood.