UK Justice Forum 🇬🇧
Disappeared and Abducted Children and Young Adults => Madeleine McCann (3) disappeared from her parent's holiday apartment at Ocean Club, Praia da Luz, Portugal on 3 May 2007. No trace of her has ever been found. => Topic started by: ferryman on April 18, 2016, 09:23:33 AM
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I've long tended to the view that it must be possible for a single and simple reason.
The US Forensic Canine Program broke with a hallowed tradition of (conventionally) both US and (specifically) English law enforcement (but not Scottish) in ruling as admissible (evidence in court) uncorroborated cadaver-dog alerts.
Indeed, under the auspices of the FCP, an uncorroborated cadaver-dog alert was taken as proof in its own right of murder, and I long argued that that could only be because dogs working for that (US) program had been de-conditioned to the scent of blood.
But (argued those who objected to this view-point) how do you de-condition a dog to a specific scent?
Well, a paper found by Pathfinder (on another thread) suggests you can (de-condition a dog to specific scents).
Here is the relevant section from the paper Pathfinder found:
6) Dogs used to develop probable cause based upon residual scent must be negatively conditioned to human urine, feces, and semen[/u] in order to ensure that the animal will not alert when encountering these substances during a search. All dogs, no matter what level of training, used in the detection of decomposed human tissue should be negatively conditioned to the scent of decomposed non-human tissue. It must be kept in mind, however, that many dogs will react or show interest to any decomposed tissue at certain short times during the decomposition process.
http://www.csst.org/forensic_evidence_canines.html
So.
If you can de-condition a dog to those scents, why not blood?
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To add to my opening post, under the auspices of the (US) FCP, a cadaver dog would be teamed up with a second dog, specifically trained to react to the scent of just blood, so that the (potential) advantage to an investigation of finding blood would not be lost.
The weakness of the Eddie-and-Keela combination was always that both dogs would react to the scent of blood.
Of course, Keela was a late add-on long after Eddie had commenced operational service; distinct from dogs working for the FCP, where two dogs would be trained in tandem to operate as a team with distinct and unique (from each other) scent-detecting capabilities.
There was no overlap; rather, separate and discrete capabilities.
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Eddie was already an old dog, already conditioned to scent blood when his training as a Cadaver Dog began. This was a recipe for confusion.
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Eddie was already an old dog, already conditioned to scent blood when his training as a Cadaver Dog began. This was a recipe for confusion.
"Training a cadaver dog requires regular contact with human blood, decaying flesh and bones. "
Meet Badger, Spud, Muzzy and Tito - highly trained specialists and crime fighters.
All four of the team went to Portugal in June last year, working with the Metropolitan Police.
But what is it that makes these springer spaniels so skilled? Partly, it’s because their olfactory glands - in their noses - are 400 times more powerful than a human’s.
Pc Newman said: “The dogs are tasked with looking for evidence which can be a minuscule piece of evidence like a blood drop which is pin-prick sized.”
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"Training a cadaver dog requires regular contact with human blood, decaying flesh and bones. "
Meet Badger, Spud, Muzzy and Tito - highly trained specialists and crime fighters.
All four of the team went to Portugal in June last year, working with the Metropolitan Police.
But what is it that makes these springer spaniels so skilled? Partly, it’s because their olfactory glands - in their noses - are 400 times more powerful than a human’s.
Pc Newman said: “The dogs are tasked with looking for evidence which can be a minuscule piece of evidence like a blood drop which is pin-prick sized.”
But the dogs can't explain the difference.
However, this Thread is about desensitising dogs who have earlier been taught one thing and now need to forget that in favour of a new thing.
I don't know if this is possible, but Eddie was too old and seasoned by the time he was retrained to include Cadaver Odour.
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But the dogs can't explain the difference.
However, this Thread is about desensitising dogs who have earlier been taught one thing and now need to forget that in favour of a new thing.
I don't know if this is possible, but Eddie was too old and seasoned by the time he was retrained to include Cadaver Odour.
Eleanor, how do you know what Eddie could or could not do ?
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Eleanor, how do you know what Eddie could or could not do ?
We all know he alerted to Blood. And presumably Cadaver Odour. So he hadn't been desensitised.
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I've long tended to the view that it must be possible for a single and simple reason.
The US Forensic Canine Program broke with a hallowed tradition of (conventionally) both US and (specifically) English law enforcement (but not Scottish) in ruling as admissible (evidence in court) uncorroborated cadaver-dog alerts.
Indeed, under the auspices of the FCP, an uncorroborated cadaver-dog alert was taken as proof in its own right of murder, and I long argued that that could only be because dogs working for that (US) program had been de-conditioned to the scent of blood.
But (argued those who objected to this view-point) how do you de-condition a dog to a specific scent?
Well, a paper found by Pathfinder (on another thread) suggests you can (de-condition a dog to specific scents).
Here is the relevant section from the paper Pathfinder found:
http://www.csst.org/forensic_evidence_canines.html
So.
If you can de-condition a dog to those scents, why not blood?
It actually says "negatively conditioned", though. I understand that to mean "trained to ignore" - i.e., alerts to the unwanted substance don't get a treat.
My understanding is that if a dog is cross-trained, it will react to what it was originally trained for, plus whatever new substance is added to the training.
I don't see how you can successfully actively decondition a dog to something once it has already been trained to find it: if a dog has been rewarded for a correct alert to substance A for years, then all of a sudden no longer gets his treat for it, then you get one very confused dog.
I don't see how a dog could be trained not to react to blood when it's a core component of (or would be in close proximity to) the human remains it's meant to be searching for.
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We all know he alerted to Blood. And presumably Cadaver Odour. So he hadn't been desensitised.
Why would you desensitise to blood?
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Well it started off as a good idea.
It might pay to establish the principles actually do apply before making assumptions on the detail.
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"Training a cadaver dog requires regular contact with human blood, decaying flesh and bones. "
Meet Badger, Spud, Muzzy and Tito - highly trained specialists and crime fighters.
All four of the team went to Portugal in June last year, working with the Metropolitan Police.
But what is it that makes these springer spaniels so skilled? Partly, it’s because their olfactory glands - in their noses - are 400 times more powerful than a human’s.
Pc Newman said: “The dogs are tasked with looking for evidence which can be a minuscule piece of evidence like a blood drop which is pin-prick sized.”
so the task of the dogs is to look for evidence...something I have been saying for some time
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so the task of the dogs is to look for evidence...something I have been saying for some time
You said the dogs didn't find any in error. Samples were taken and stored. It's not up to the dogs to prove who they came from.
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Why would you desensitise to blood?
Simply this.
Uncorroborated cadaver dog alerts (traditionally) are not accepted as stand-alone evidence of murder because there is always the chance that the dog might have reacted to the scent of blood.
If you de-condition a (cadaver) dog (to the scent of blood) you can have greater certainty that if the dog reacts, the dog has, indeed, reacted to the scent of cadaver-odour.
At the same time, because you have a second dog, trained to react to nothing but blood, you don't lose the ability to find blood if blood-deposits are present at the crime-scene and you have a dog to detect it.
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Simply this.
Uncorroborated cadaver dog alerts (traditionally) are not accepted as stand-alone evidence of murder because there is always the chance that the dog might have reacted to the scent of blood.
If you de-condition a (cadaver) dog (to the scent of blood) you can have greater certainty that if the dog reacts, the dog has, indeed, reacted to the scent of cadaver-odour.
At the same time, because you have a second dog, trained to react to nothing but blood, you don't lose the ability to find blood if blood-deposits are present at the crime-scene and you have a dog to detect it.
It's why you have a blood dog as well. To discount cadaver dog alerts that are also alerted by blood dog. You need them to alert to blood as it is a major indicator off something serious. Blood usually remains inside bodies unlike other fluids frequently mentioned.
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It's why you have a blood dog as well. To discount cadaver dog alerts that are also alerted by blood dog. You need them to alert to blood as it is a major indicator off something serious. Blood usually remains inside bodies unlike other fluids frequently mentioned.
There is no advantage to two dogs trained to react to the same scent (the position with the Eddie-and-Keela combination).
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"To successfully cross train a dog requires a few rules that cannot be broken. First, you must be able to clearly communicate to the dog, exactly what the task is and the circumstances.
Next, you must use a different command/word for each discipline so that the dog knows what you expect him to do. The dog must have a different signal for each discipline. For example, one signal for HRD, one for live finds, one for drowning, etc. Lastly, you must trust your dog and be able to "read” what the dog is communicating to you.
The only drawback to cross training a dog is that some authorities will not trust the dog’s findings if they are cross trained. They may feel that the dog could make a mistake and the evidence may not hold up in court".
http://cadaverdog.com/index.php
You could always have a five quid whip among 13 of you and buy Andy's book!
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(https://i.imgsafe.org/56746d6.jpg)
(https://i.imgsafe.org/211e8e2.jpg)
(https://i.imgsafe.org/fd182d2.jpg)
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You said the dogs didn't find any in error. Samples were taken and stored. It's not up to the dogs to prove who they came from.
so what evidence did they find
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so what evidence did they find
Keela alerted in a number of places for blood. Forensics found none.
'Keela' The Crime Scene Investigation (C.S.I.) dog will search for and locate human blood to such small proportions that it is unlikely to be recovered by the forensic science procedures in place at this time due to its size or placement.
Forensic testing may not produce evidence but any alert may provide intelligence to support other factors in the investigation of a crime.
http://www.mccannpjfiles.co.uk/PJ/MARTIN_GRIMES_PERSONAL.htm
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But the dogs can't explain the difference.
However, this Thread is about desensitising dogs who have earlier been taught one thing and now need to forget that in favour of a new thing.
I don't know if this is possible, but Eddie was too old and seasoned by the time he was retrained to include Cadaver Odour.
Not quite!
This thread is about training two dogs (from scratch) distinct and different and different disciplines, one to react to cadaver scent (not blood); the other blood (not cadaver scent).
To do that, you need to desensitise a dog to certain scents.
I agree it seems counter-intuitive to suppose that you can.
But the reference in the link Pathfinder found suggests it is, indeed, possible.
Just no clue how.
And the (potential) advantage (of a desensitising a dog to the scent of blood) is that you can have greater certainty that if your (cadaver) dog does react, it has detected cadaver-scent, you can have greater certainty that the dog has, indeed, reacted to a cadaver scent and can use that as stand-alone evidence of murder.
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Keela alerted in a number of places for blood. Forensics found none.
'Keela' The Crime Scene Investigation (C.S.I.) dog will search for and locate human blood to such small proportions that it is unlikely to be recovered by the forensic science procedures in place at this time due to its size or placement.
Forensic testing may not produce evidence but any alert may provide intelligence to support other factors in the investigation of a crime.
http://www.mccannpjfiles.co.uk/PJ/MARTIN_GRIMES_PERSONAL.htm
You don't think that might have been Grime, covering all bases for if a dog alerts and no (forensic) evidence is found?
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Not quite!
This thread is about training two dogs (from scratch) distinct and different and different disciplines, one to react to cadaver scent (not blood); the other blood (not cadaver scent).
To do that, you need to desensitise a dog to certain scents.
I agree it seems counter-intuitive to suppose that you can.
But the reference in the link Pathfinder found suggests it is, indeed, possible.
Just no clue how.
And the (potential) advantage (of a desensitising a dog to the scent of blood) is that you can have greater certainty that if your (cadaver) dog does react, it has detected cadaver-scent, you can have greater certainty that the dog has, indeed, reacted to a cadaver scent and can use that as stand-alone evidence of murder.
TBH... I don't quite follow, FM.
How on earth can you desensitise a dog to the scent of blood when it's part and parcel of what it's supposed to be searching for, which even then requires eliminating innocent explanations?
Which part of a decomposing human would you train it on that doesn't contain blood or hasn't been in close proximity to any?
It may be possible at some time in the future to physically isolate potentially suspicious VOCs not associated with human blood, nor in a combination of VOCs that can't be found in nature or in any naturally occuring situation and present them with advanced pseudo-scents... but that doesn't seem to be the state of affairs at the moment.
The bottom line - in this case - is that there was no forensic evidence of blood, nor of anything else aside from some incomplete DNA of no particular investigative value.
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TBH... I don't quite follow, FM.
How on earth can you desensitise a dog to the scent of blood when it's part and parcel of what it's supposed to be searching for, which even then requires eliminating innocent explanations?
Which part of a decomposing human would you train it on that doesn't contain blood or hasn't been in close proximity to any?
It may be possible at some time in the future to physically isolate potentially suspicious VOCs not associated with human blood, nor in a combination of VOCs that can't be found in nature or in any naturally occuring situation and present them with advanced pseudo-scents... but that doesn't seem to be the state of affairs at the moment.
The bottom line - in this case - is that there was no forensic evidence of blood, nor of anything else aside from some incomplete DNA of no particular investigative value.
Let's put it like this.
If you can train a dog to detect only blood (it seems you can, Keela was thus trained, and the whole point of the tandem-team is that one dog detects only blood; the other, only cadaver-scent) then how was the blood-dog desensitised to cadaver-scent?
It must have been, because otherwise, you can't call it a blood-dog.
And it seems you can train a dog to discriminate between scents, not that it detects (obviously all dogs will detect all scents, irrespective of training) but that it will react to
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Not quite!
This thread is about training two dogs (from scratch) distinct and different and different disciplines, one to react to cadaver scent (not blood); the other blood (not cadaver scent).
To do that, you need to desensitise a dog to certain scents.
I agree it seems counter-intuitive to suppose that you can.
But the reference in the link Pathfinder found suggests it is, indeed, possible.
Just no clue how.
And the (potential) advantage (of a desensitising a dog to the scent of blood) is that you can have greater certainty that if your (cadaver) dog does react, it has detected cadaver-scent, you can have greater certainty that the dog has, indeed, reacted to a cadaver scent and can use that as stand-alone evidence of murder.
From the document linked by PF and me sometime ago the csst jobby.
"Unfortunately, in such a situation the trier of fact may easily be misled as to both the accuracy and precision of the dog's actions: Accuracy in the sense that the dog (depending upon its level of training) may be reacting to something other than residual scent from decomposed human tissue; precision in that the dog may be reacting correctly to the scent of decomposed human tissue, but imprecise in the sense that the dog is not differentiating between whose decomposed human tissue is giving the scent".
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From the document linked by PF and me sometime ago the csst jobby.
"Unfortunately, in such a situation the trier of fact may easily be misled as to both the accuracy and precision of the dog's actions: Accuracy in the sense that the dog (depending upon its level of training) may be reacting to something other than residual scent from decomposed human tissue; precision in that the dog may be reacting correctly to the scent of decomposed human tissue, but imprecise in the sense that the dog is not differentiating between whose decomposed human tissue is giving the scent".
So a dog can't differentiate between the decomposed human tissue of person A or the decomposed human tissue of person B.
Irrelevant to the point we are discussing.
Can you train a dog to differentiate between the specific material blood and non-blood-based remnants of a corpse?
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Let's put it like this.
If you can train a dog to detect only blood (it seems you can, Keela was thus trained, and the whole point of the tandem-team is that one dog detects only blood; the other, only cadaver-scent) then how was the blood-dog desensitised to cadaver-scent?
It must have been, because otherwise, you can't call it a blood-dog.
And it seems you can train a dog to discriminate between scents, not that it detects (obviously all dogs will detect all scents, irrespective of training) but that it will react to
If a dog ONLY gets a reward in reaction to an isolated substance (in Keela's case dried human blood), isolated or mixed with other substances, then she only gets her treat when that is present.
Eddie was a wide-spectrum dog to narrow down the initial area of potential interest.
Let's try this a different way. Eddie smells anything with sugar. In theory, anything without sugar will be ignored. He reacts. A different dog, an expert in chocolate detection, is wheeled in to check if the sugar-marked areas show any sign of cocoa, a component of chocolate.
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So a dog can't differentiate between the decomposed human tissue of person A or the decomposed human tissue of person B.
Irrelevant to the point we are discussing.
Can you train a dog to differentiate between the specific material blood and non-blood-based remnants of a corpse?
I think that you'd need to turn the question on its head: the first to be wheeled into a specific area for inspection is the GP. If the GP alerts, you call in a specialist to narrow the field for further examination and send off samples for lab analysis.
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So a dog can't differentiate between the decomposed human tissue of person A or the decomposed human tissue of person B.
Irrelevant to the point we are discussing.
Can you train a dog to differentiate between the specific material blood and non-blood-based remnants of a corpse?
It would be relevant in the case of murder.
You raised the issue of murder not me. So you have made it relevant.
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It would be relevant in the case of murder.
You raised the issue of murder not me. So you have made it relevant.
A dog's ability (or inability) to distinguish between (deceased) person A or (deceased) person B is not the subject of discussion (irrespective of the cause of death).
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It would be relevant in the case of murder.
You raised the issue of murder not me. So you have made it relevant.
I don't see where FM mentioned murder.
A problem seems to have been the assumption that "body fluids" should somehow be assumed to mean post-mortem ones.
That doesn't appear to be the case as Grime admitted (later, when asked) that the dogs would react to dried blood from LIVING people).
For some reason, some people in certain quarters appear to have steadfastly ignored that for reasons best known to themselves and continue to do so despite claiming to be experts on the files. At least one person set up some kind of 'study group' with only partial information (including long-debunked tabloid extracts) as material to, erm, study.
Why?
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I don't see where FM mentioned murder.
A problem seems to have been the assumption that "body fluids" should somehow be assumed to mean post-mortem ones.
That doesn't appear to be the case as Grime admitted (later, when asked) that the dogs would react to dried blood from LIVING people).
For some reason, some people in certain quarters appear to have steadfastly ignored that for reasons best known to themselves and continue to do so despite claiming to be experts on the files. At least one person set up some kind of 'study group' with only partial information (including long-debunked tabloid extracts) as material to, erm, study.
Why?
You replied to the post where he mentions murder!