Steve Guest wants to know why we call people experts just because they do things we do not understand



The field of digital forensics was, in the main, pioneered by law enforcement. Police officers and support staff beavered away (in my case, in a cupboard) using rudimentary tools, effectively to create a new discipline.



These enthusiastic amateurs, often working with little official management support, managed to adapt their training in the preservation of evidence to create principles that remain in force to this day.



Training gradually became available. The field developed and has become fully recognised. There are now maybe a couple hundred officers and civilian investigators in the UK. Some of these are leaders in the field and every bit the equal of the best independents.



In one respect, however, they remain second-class citizens. During the years I investigated hi-tech crime, I encountered many individuals retained by the defence to provide an opinion. Some were well-trained professionals with a wealth of experience. Others, however, included (literally) the chap who ran the local computer shop, or the man who was prepared to swear that an image was too small to be visible, until it was proved by example to fill the computer screen. There was also a charming gentleman who had never actually used Windows XP and took screenshots with a 35mm camera.



The one thing that these people had in common was that they were retained as 'expert witnesses'. What was equally clear was that, while they may have possessed expertise in some area of computing, it was not in the field of the extraction, analysis and investigation of digital evidence. Police officers, in contrast, are invariably presented, regardless of experience, training or ability as 'trained practitioners'.



It is truly regrettable that the mere production of a 'defence expert' appears to bring some prosecutors to the verge of capitulation. I am fully aware that the duty of an expert is to the court, but then I rather thought my duty as a police officer was to see justice done - even if that meant a case failed to reach court.



It's an odd world - the day I retired, people were eager to call me an 'expert', while some to whom I look in awe will remain 'trained practitioners' for years to come.



Steve Guest ran North Yorkshire Police's hi-tech crime unit, and now runs the computer forensic company Hitecc Forensics (www.hitecc.co.uk)