Police, Camera, Action!

November 1, 2003

In March 2003 Home Secretary, David Blunkett made a stunning announcement at the Wakefield Bureau of the national VIPER (Video Identification Parade Electronic Recording) project. “Its nice to be part of a government IT scheme that actually works!” he said as he was given a tour of the facility which has already revolutionised the way police ID parades are carried out. The site, which houses the supercomputer system capable of delivering the national video programme represents something of a triumph for its designers, the so-called VIPER’s nest from West Yorkshire‘s Video Unit.

Successful identity parades are an essential part of the fight against crime for the UK‘s police forces. However, ‘live’ line-ups, in which witnesses are invited to a police station to view eight to ten volunteers and the suspect from behind a one-way glass screen, often take up to ten weeks to arrange and cost around £1000. Moreover, more than half of all such traditional ID parades are abandoned due to lack of suitable volunteers or suspects failing to attend.

Video id parades, which were given equal evidentiary weight as live line-ups in April 2002 when the PACE Codes were revised, offer distinct advantages. A virtual parade can be organised and delivered in just 30 minutes and costs just £150. With a database of clips of nearly 11,000 volunteers, even distinctive looking suspects for whom it would be almost impossible to find look-alikes in the proximity of a particular police station can be processed using VIPER.

It is not surprising, then, that abandonment rates have dropped substantially (reduced to just 10% in areas where VIPER has been in use). The national system is expected to save the Home Office £143million over the next five years. Perhaps more importantly, VIPER is expected to increase detection rates as identification can be organised and carried out while the suspect is still in custody. This not only prevents the suspect from absconding when called to appear in an id parade but witnesses are also more likely to provide accurate information while the incident is fresh in their minds.

What is VIPER

The VIPER system consists of a database of video clips linked to 32 editing suites all housed at a data centre in Wakefield. The Linux-based system incorporating 1.4TB of storage space is built around industry standard hardware configured as a Linux cluster. This fits with West Yorkshire Police’s existing Linux infrastructure and that helped to keep costs low. The latest in secure, reliable and highly available IBM hardware, including two IBM Total Storage FAStT 500 servers, two IBM SANs and an LTO tape library underpin the solution. This is supported by Tivoli TSM automated data management and a remote monitoring tool, WatchDog, developed by storage firm Sagitta. It uses IP virtual private network technology from Cable & Wireless. The C&W IP VPN takes 15 to 20 minutes to download IDs to individual police stations – these can even be burnt onto DVDs to be shown to victims at home or in hospital. Live video links to suspects on remand in prison are also now starting to take place.

Development of VIPER

The story of VIPER’S development began back in 1996 at the Video Unit of West Yorkshire Police in Wakefield. I supplied the unit with equipment for editing miscellaneous video tape from CCTV and ad hoc footage supplied by various sources into a recording which could be used as evidence in court.

Pat Prince, Head of the Video Unit, had put together the occasional video ID parade but found the process to be exceptionally laborious. Although the unit had built up a database of several hundred clips of volunteers which could be used in a video line-up, these were not indexed as such and could be referenced only by browsing a book of still images. Moreover, the selected clips could be retrieved and edited only in a linear fashion using a traditional tape based editing system. Anyone who has prepared a bespoke VHS cassette from pre-recorded footage using two VTRs will recognise the painstaking process of fast forwarding to locate a particular clip and then recording it to the other tape. Using this method it could take many hours for Pat to prepare an 8/9 clip video id parade.

In late 1996, the purchase of a non-linear video edit suite provided the first real breakthrough. Using the FAST Video Machine system Pat was able to search and retrieve clips in a fraction of the time. The FAST Video Machine system was one of the most successful products in the first generation of PC-based edit suites and lasted the unit approximately four years. During this time it was connected to probably the largest amount of storage in use on that system, anywhere in the world.

We then turned our attention to the delivery system, which was, at that stage, carried out by physically transporting a VHS cassette featuring the video id parade using a courier or police pursuit car. Pat was aware that, if we could prepare and deliver the video in, say, less than three hours, the ID parade could be performed while the suspect was still in custody and that immediacy had a number of benefits.

I set about working on a digital solution which would allow the virtual line-up to be transmitted down a telephone line. We looked at various video capture cards but were mindful of the importance of quality. We had to ensure that the ID parade could not be challenged on technical grounds in court.

The launch of the FAST AV Master video card in 1997 provided the solution. FAST’s accompanying edit suite also speeded up the edit process. However, while the digital video solution had solved the problem of edit times, it had created another in terms of file sizes. Each video clip was about 50MB; even using an ISDN2 line at 128KB/sec it would take hours to transmit a whole id parade. What’s more, connectivity problems meant that the whole download could fail if one of the connections was interrupted at any time. We decided to call on the expertise of Matek Business Systems, one of the early partners in the development of the system, who provided a multiplexing solution which improved connectivity.

In 1998 a site trial was conducted at a police station in Bradford. There, a video ID unit was installed which consisted of a low-light camera and housing mounted on a wall, a couple of lights, a standardised grey cloth backdrop and a capture PC. This was linked to the Wakefield Video Unit, initially via an ISDN line but that was later replaced by a 2MB leased line. The site trial was extended a year later to include stations at Leeds, Halifax and Wakefield.

As its popularity increased, the original equipment and system architecture started to creak under the strain. Due to the sheer volume of data being processed, certain elements were displaying signs of fatigue. The FAST Video Machine suite and its proprietary 180GB hard drive system was replaced by the state-of-the-art Pinnacle silver edit suite, which used advanced MPEG2 compression. This technology offered improved picture quality, whilst reducing the file sizes of the captured video by over 50%.

The next significant development occurred with the introduction of the Canopus Amber card in 2000 – this captured video as mpegs rather than mjpegs. It also further reduced the file sizes by 50% and thus improved transmission speeds accordingly. We also knew that in theory the MPEG2 files created by the Amber should work with the source edit files in the silver edit suite. We put that theory into practice with the help of Pinnacle Systems in Munich.

At last we were able to create a system with file compatibility right from capture at the police station, through the edit process and onto DVD (also MPEG2) for the final viewing of the parade.

The force wide trial had proved the VIPER system as a concept and official acknowledgment came with the announcement in early 2002 that the Home Office was granting £7.6 million funding for a national VIPER system. The programme was linked to the government’s Street Robbery Initiative. The VIPER system would be rolled out to at least seven stations in ten robbery hotspots in the UK.

The ramifications, in terms of scale, meant that I needed to call in technical expertise in storage and file delivery. This came in the form of Sagitta, a leading company in storage technology. Without a major breakthrough in digital video compression, and having discounted the feasibility of video streaming, we had to find a way to manage the massive amounts of data processing required to edit video ID parades on a national system.

At an exhibition in Las Vegas some two years before, Phil Ball of Sagitta had been introduced to IBM’s new General Parallel File System (GPFS). This had until then only been used in supercomputer applications that needed to process vast amounts of data such as seismic surveys. Although this technology had never been applied to video before, we quickly realised that only GPFS would give us the speed of access to the vast video database necessary to edit ID parades on a national basis.

In May 2002 Sagitta starting work building a fully scaled pre-stage VIPER system at their premises in Havant which consisted of 32 edit suites built, installed and configured by Quadrant. In just five months the national VIPER system was delivered to a new site in Wakefield as a working system. Quadrant provided training for the 20 full-time editors who now provide a 24-hour service to the 58 video id suites in police stations across the country.

Since April 2002 over 15,000 video ID parades have been carried out using VIPER and the system now prepares over 80 video ID parades every day to 13 police forces and there are orders in the pipeline for 20 new units. The original system, which runs on IBM xSeries Linux processors and ‘Intellistations’ for video editing, plus software and services from Sagitta, cost about £1.3m. The next stage is to develop a National Video Identification System [NVIS] in which VIPER will be linked to other identification systems such as DNA, digital fingerprints, facial and iris recognition, which are held in different databases, and make the information accessible to police on the move.

How VIPER works

Suspects are filmed in a VIPER video ID suite in a police station. They are asked to face forward and turn their heads to either side. Thirty seconds of footage of the suspect’s head and shoulders is recorded and transmitted via an IP network to the national VIPER Bureau. There it is edited down to a 15-second clip by one of the 20 editors located in the Wakefield centre. If necessary, they can make adjustments such as colour correction using the Pinnacle Liquid silver NLE system.

Meanwhile, the suspect and his solicitor are invited to choose 8/9 candidates from an initial selection of still images indexed by various attributes and features (such as hair colour, ethnic background, skin colour and age) and created by entering a general description of the suspect. The selection is forwarded to the editors in Wakefield who extract the relevant clips. These are added to the clip of the suspect to create the video line-up. This is the transmitted down the IP line back to the download PC at the police station where it can be viewed or burned onto DVD.

Andy Hogben is the national sales manager of Quadrant Visual Solutions, a Nottingham-based company which provides state-of-the-art audio-visual and communications solutions to commerce and industry.