Imaging technology used by the police is changing rapidly in line with the growing availability of evidential images. Managing the volume of images now being generated is as much of a challenge to the police as taking, collecting and analysing those images.
The proliferation of digital cameras, CCTV cameras, mobile phones and other forms of capture device means there are more opportunities now for detecting crime aided by imagery than ever before.
West Yorkshire Police Imaging Unit is one of the leading police imaging facilities in the UK. We are part of the Scientific Support Department of West Yorkshire and so work closely with colleagues dealing with other forensic and scientific evidence. The Imaging Unit has a variety of specialist teams working in a range of disciplines and provides a service to the whole force from our base in Wakefield.
Image Capture
The Unit has a team of multi-skilled Imaging Officers who attend a variety of assignments in order to capture the required images. As we work a shift pattern covering 7 days a week from 6 am to 10 pm with a call-out rota during the night, the assignment could be at any time of the day.
Working with digital still photography or with video cameras as appropriate to the subject, an Imaging Officer’s working day can be varied and challenging. Attending a serious crime scene or road traffic accident to supplement the photographic work of the Scenes of Crime Officers; evidence gathering with cameras at football matches or producing multi-media packages for presentation in court is all in days work.
We also provide imaging for police non-crime events too such as press photos and videos, exhibition and publicity material and police training programmes.
Imaging Officers need to be conversant with all modern post capture skills such as computer image processing software (e.g. Adobe Photoshop) and computer based video editing software.
Computer generated imaging is a growing area of our services and interactive electronic images are becoming commonplace in West Yorkshire. Three dimensional crime scene reconstructions’, body mapping images (where injuries and other real-life details are incorporated within a generated image) is amongst the specialised work of the unit.
We have a further specialist technical photography section who use a variety of scientific and forensic techniques to produce photographs of fingerprints and footprints recovered from scenes. The good quality images that result, often revealing details not visible to the naked eye, are passed to our colleagues in other departments who can identify the owner of the marks from our photographs.
Image Processing and Analysis
We have a team of technicians who manage the image databases and ensure all images used by the police and courts are of the appropriate quality and consistency. We also put a great deal of emphasis on the correct storage of our images as well as the systems needed to retrieve and when appropriate, remove them.
Our Image Analysis section works mainly with CCTV images. We employ state-of-the-art facilities in a time when science and technology are increasingly essential in proving the facts in a case. This technology includes facial recognition systems, height analysis, clothing comparisons and more. Our technical officers often attend scenes of crime to recover digital CCTV evidence from modern computer based systems to secure the footage. Back in the laboratory we have a variety of specialised image enhancement systems that we use to bring out the highest quality of detail possible from what are sometimes poor quality originals.
The digital imaging technology employed is evolving quickly and our technical staff and the police generally must keep apace of this change. Image Analysis Officers are as conversant with computer hard disc examination as they are in analogue tape enhancement.
Presentation of Evidence at Court
With the increasing reliance on scientific evidence in order to prove a case and establish the facts, there is a tendency for this evidence to become ever more complex. In addition, the sometimes large volume of evidence, including images of all types, often mean that presenting the facts of a case in the courtroom is becoming reliant on imaging techniques.
Particularly in the larger or more serious cases the Imaging Unit in West Yorkshire employs all of the presentational skills in creating multi-media electronic presentations, delivered by computer, and encapsulating all the relevant evidence.
Within this package of evidence may be 360-degree images of the crime scene, 3-D reconstructions of important details in the case, video edits and interactive maps and plans. Sound recordings and any other evidence in the case are also included.
The effect in the courtroom is for the evidence to be concise, readily understandable by any jury and concentrate attention on the key facts being presented in a visual as well as verbal delivery.
The presentational packages are collaborative efforts involving many imaging specialists who bring their own particular expertise to the production. The strength and diversity of our specialist imaging staff in West Yorkshire means that we are frequently consulted by other police forces and agencies for help and advice.
Other Specialist Sections
The Imaging Unit provides an e-fit service whereby witnesses of a crime can be interviewed in their homes and encouraged to describe the appearance of the offender they have seen. Using the delicate skills required to encourage such memory recall, our police artists create a computer generated facial likeness. These composite images are called e-fits and are used in appeals, wanted posters and by CrimeStoppers.
We have a team of Crime Scene Draughtspersons who attend scenes to survey, measure and produce forensically accurate drawing and plans. These are created using the latest electronic measuring instruments and CAD drawing packages in either 2D or 3D. We also incorporate Ordnance Survey mapping and vertical air photography into our drawings as necessary.
National V.I.P.E.R. Bureau
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