If you are looking for Glamour, Gadgets and Grissom you won't find them here. Forget what you think you know about 'Forensics', these are the tales of one man and his brush. Of course these views do not represent the views of any Police Force or indeed reflect any Force Policies ya da ya.

Monday 24 December 2007

Happy Christmas


Well, I have managed to keep this blog going longer than I thought and that is down to you good people dropping by every once in a while and leaving nice comments. So Happy Christmas to you and yours and I hope enjoy yourselves whatever your plans are.

Thankfully I'm not working this Christmas, so I'll miss out on the inevitable Suicides, crying kids (whose presents have been nicked by Billy Burglar) and the droves of Officers who say 'Oh!, I didn't know you worked on Christmas Day!, can you just check this.....'. Go away I'm trying to get all my work done so I can sneak off early!!

Anyway until the New Year have a good 'un and if you are working have a 'q' un! HAPPY CHRISTMAS!

Friday 21 December 2007

Low Copy Number

A judge has ordered an immediate review of LCN DNA following the Omagh Bomb verdict. For those unaware of what LCN (Low Copy Number) DNA is, it is basically a super-sensitive technique that can extract DNA from areas touched or handled by someone, that sample is then amplified, a bit like photocopy enlarging, until a usable profile is obtained. This profile is nowhere near as accurate as a full profile obtained from something like Saliva or Blood which would have a discriminating factor of 1 in a Billion of being anyone else, instead a LCN profile can give you a much more ambiguous result giving you a huge list of names of who it could be instead of who it most likely is. This list of names could be whittled down by Detectives based on geography, offender description or maybe flag up the name of a known suspect.

I would liken this type of evidence to that of a fairly tenuous eye witness account, it gives you an idea of who it might be but not enough to be used as evidence. In general Policing terms it's better known as intelligence and not something that you would base your prosecution on. I'm not sure in what form this LCN evidence was used in the Omagh case but to base your whole case around it would be foolish and at most circumstantial.

It would be a shame however if the FSS withdrew this technique in future as it is a very useful intelligence tool. I have had some great results in previous jobs where an offender wasn't known and just being given a name has opened up so many other lines of enquiry and other evidence gathered has come back to these people. On the plus side at least some of the clueless Police Officers will stop asking for us to swab every door handle in sight on the off chance that the force may fork out a couple of grand to process them.

Monday 10 December 2007

Negatives

So there I was called out in the middle of the night to an Arson attack at a dwelling on the 7th floor of a block of flats. By the time I got there the Fire Brigade had made some initial enquiries and it turns out it was caused by the occupant who had be suffering from mental issues of late and this was his latest episode.

During the investigation the now homeless occupant turns up with a full and frank admission of starting the fire himself in the bedroom. Along with the Fire Officers we confirmed the seat of the fire in the bedroom, there were no other signs of forced entry (other than the size 9s of the first Fireman) or anything out of the ordinary apart from all his possessions now being a nice shade of black.

All that was required of me at this stage was photographs of the scene. This may sound like a quick task, but when it's pitch black outside and all the walls inside are pitch black the rules of photography change somewhat making it a more laborious task. In order to record all of the detail in a darkened room the use of flash is not enough as it creates as many shadow areas as it illuminates. So using timed exposures of between 15 secs and 1 Minute on a tripod mounted camera with fill in flash extends the average shot from a 125th of a second to a few minutes per shot. There will probably be at the very least four shots per room in a flat with six rooms so the total time of this type of job can take a good couple of hours.

Imagine my horror then when I had finally taken the last shot to find I had no film in the camera! There were a couple of officers still waiting for me to finish, hiding my mistake quite well I say 'Just changing films, got a couple of final shots to make and I'll be done.' Luckily at this stage it was very early morning and the sun was starting to poke itself over the horizon, so I quickly fly around all the rooms using the camera and flash handheld, five minutes later I have the shots I need, I pack up and leave. A week or so later the photos arrive on my desk and all things considered they didn't turn out too bad, not my best work but a lucky escape nonetheless. Thank god for Digital!