Recognising changes in visual representation of clothing in CCTV imaging

Abstract

Purpose – Closed circuit television (CCTV) imaging is an increasingly used technology and it is now common place for law enforcement to access CCTV footage as an investigative tool to assist in the nomination of a person of interest, or to aid in the prosecution of an offender. The purpose of this paper is to discuss the role of imaging practitioners in the analysis and interpretation of CCTV images within a law enforcement context. It explores and addresses the limitations of CCTV imaging in evidence with a focus on the interpretation of changes in the visual representation of clothing items. Design/methodology/approach – This paper demonstrates the variations observed in four dark toned garments imaged using one CCTV camera with two different recording settings – visible light and near infrared. The device used was installed and operated in a manner comparable to that used in the public domain, the resulting images indicative of those experienced in casework. Findings – The results display a noticeable change to the tonality of each clothing item between the varied recording conditions. These inconsistencies highlight the limitations of layperson analysis and identify the importance of the inclusion of imaging practitioners when interpreting and analysing such images as evidence. Originality/value – With an abundance of images in the society, layperson interpretation has become common place. Recognising the value of trained imaging practitioners who can assist law enforcement in analysis and interpretation is paramount to ensuring CCTV images as evidence are used appropriately.