Can I just throw in here, since people seem to be mentioning it a lot, that forensic testing, specifically DNA testing as a part of an active line of enquiry ought to be consigned to the rubbish bin of history.
If you're using it as the icing on the cake of a well worked investigation then maybe it has some merit, but using it as an investigative tool just leads to lazy Policing, lazy investigating, lazy thinking, and dismal outcomes.
Especially in the UK where we use the "more akin to witchcraft than science" of low copy number DNA profiling.
I was going to use fairies as an example, but lets use squirrels instead.
Suppose someone says to you that a squirrel was seen in an specific area, and I say to you that I don't believe squirrels exist, you can prove me 100% wrong by going out and coming back with a squirrel in a specimen jar - there can then be no argument - squirrels clearly DO exist.
If you went out to that location but found no squirrels or evidence of them and you come back with an empty specimen jar - that does NOT prove that squirrels do not exist - it just proves you didn't find any.
I can't say "aha - I was right, you see, squirrels clearly do NOT exist". That would be nonsense, but that is eactly what happens with DNA profiling in particular.
If some DNA of Corrie as an example was found in the cab of the bin truck - some skin, blood, saliva, hair, semen, or whatever - all that this would prove is that his DNA is there.
It doesn't explain HOW it got there, it might infer a few things, but it is not proof of one thing or another, just that his genetic material somehow got there.
If you tested that cab and there is NO DNA material - that does not mean he wasn't there, or his genetic material wasn't there - just that either a) you didn't find t, or b) it wasn't deposited there.
It DOES NOT mean (like the absense of squirrels) that they/it does not exist / wasn't in that place.
But it seems like this is how the Police operate, particularly in the Uk where they like to use low copy number DNA profiling which is so full of holes it makes a swiss cheese look particularly solid.
Lets not forget that not so long ago the Police were searching for a missing girl called Tia Sharp, and despite searching the loft umpteen times they failed to find her body wrapped up in bin liners - right where it had been all alog, it was only as the summer got hotter, and the body decomposed that it became obvious that this is where she was.
So, if they can't find a whole body in a small area after numerous searches, why on earth does anyone put any faith in the notion that they'll find DNA - potentially microscopic particles in any other area?
And if they do and they use low copy DNA technoques (trying to analyse DNA that is 1 milionth the size of a grain of salt) - it's useless - read this if you don't believe it -
http://news.bbc.co.uk/1/hi/northern_ireland/7154189.stm
So they didn't find Corries DNA in the cab, or the truck or on the utside of the truck, or in the horseshoe, or the bins - SO WHAT?
What they need to do is start by THINKING then INVESTIGATING then using these tools later as the final touches.
It seems they start with them FIRST, then shape their thinking - if you can call it that - based on the outcomes.
It is not the way to go, thinking first, investigating second, testing third or later than that even.
They will never solve this if they don't get back to basic real world hands on Policing - but sadly THAT is what seems to have been consigned to the rubbish bin of history - the thing that actually works.
