Poll

Peer Reviewed Research suggests that Scent Dogs of all types have a maximunm combined accuracy of about 90%

I Understand and Accept this
18 (34.6%)
I believe Scent Dogs are more accurate than this
12 (23.1%)
I am not sure
4 (7.7%)
I don't believe Scent Dogs generally are that accurate
18 (34.6%)

Total Members Voted: 38

Voting closed: February 25, 2014, 04:23:56 AM

Author Topic: Poll - Scent Dogs Accuracy  (Read 59587 times)

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Offline Carana

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Re: Poll - Scent Dogs Accuracy
« Reply #360 on: August 22, 2015, 10:15:19 AM »
I now realise which article you're quoting from (I hadn't noticed that this thread had been resurrected).

http://www.csst.org/forensic_evidence_canines.html

That is one handler's classification of dog training and related terminology, but it doesn't appear to be universal.

Grime stated that Eddie was trained to find decomposing human remains and body fluids.

An area of confusion is what "decomposing human remains and body fluids" actually means. Dried blood from a living person is still a decomposing human body fluid. And we know that he reacts to that.

We don't know if he was trained to ignore urine, faeces, saliva, semen, etc. There is some ambiguity as to whether he reacted to semen / vaginal fluids on the Jersey sex tissues, or blood, or both.

Even if he did react to semen on the tissues, that doesn't mean that he was trained as a search and rescue dog (i.e. searching for missing living people, e.g., following a disaster), though, as that's a different specialisation. There could of course be some overlap if a VRD (victim remains dog, i.e., the more sensitive term for cadaver dog used by some handlers out of respect for victims' families) detected dried blood coming from rubble or whatever and the victim was still alive.

In disasters, they take in the S&R dogs first to search for anyone who may still be alive... then the VRDs go in to locate bodies for identification.

Personally, I tend to think that Eddie did react to semen / vaginal fluids on the tissues as he stated that the alert was within his training parameters. Keela was wheeled in aferwards and alerted to what was presumably blood. The ambiguity lies in whether he stated that before Keela was wheeled in or not.

 

Offline pathfinder73

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Re: Poll - Scent Dogs Accuracy
« Reply #361 on: April 25, 2016, 11:46:28 AM »
In the winter of 1997 through to the spring of 1998 Dr. Deb Komar of the University of Alberta, Canada conducted a study 'The use of cadaver dogs in cases of advanced decomposition: A field study in adverse recovery scenarios and animal vs human scent discrimination'. Dr. Komar worked with cadaver dog teams from the RCMP Civilian Search Dog Program now the Canadian Search Dog Association [2] and the Search and Rescue Dog Association of Alberta.[3] This study showed the accuracy rates of cadaver dogs in moderate to adverse winter weather conditions, and also the dog's' capabilities to discriminate between animal and human remains. It indicated that an accuracy rate near 100% can be achieved through careful and directed training.
Smithman carrying a child in his arms checked his watch after passing the Smith family and the time was 10:03. Both are still unidentified 9 years later.

Offline pathfinder73

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Re: Poll - Scent Dogs Accuracy
« Reply #362 on: July 25, 2016, 04:03:37 PM »
What the dog smelled: The science and mystery of cadaver dogs

Scientists still can't fully explain why some dogs are so effective at finding human remains
By Chris Oke, CBC News Posted: Jul 23, 2016

Dive teams spent 12 days searching the waters of Elliot Lake in northern Ontario and didn't find a thing.

When the cadaver dogs were called in, they needed just 15 minutes.

Six young people had been making their way home from a night of drinking on an island when their overloaded canoe capsized. Everyone made it back to shore, except for 20-year-old Vinnie Yeo.

One of the volunteers called in to help search for the body was Kim Cooper, a founding member of the Ottawa Valley Search and Rescue Dog Association, and the owner of two of the three cadaver dogs on the scene that July day in 1999.

Her Malinois named Piper was perched at the front of a boat as it slowly trolled the search area, sniffing at the water below. Fifteen minutes later, the dog turned to Cooper and let out a series of loud barks

Piper was the second dog to indicate in this spot.

The divers searched the area and found Yeo's backpack. The next day, they found a case of beer that had been in the canoe. The day after that, they found his body.

"It was quite a deep find," Cooper said. "Yet at the same time, the dogs were absolutely positive that they had him."

Not only can these dogs detect the scent of human remains under 30 metres of water, some can also detect traces as small as a shard of bone or drop of blood. They can also tell the difference between, say, a dead raccoon and a dead hiker.

And yet scientists still aren't 100 per cent sure how they do it and the training community is still figuring out how to train them most effectively.

'Body Farm'

"Most think an odour is just made of one chemical, when in reality it is made up of dozens or hundreds of chemicals," said Arpad Vass, a research scientist at the Oak Ridge National Laboratory in Tennessee.

Vass is a leading expert on decomposition odour analysis, and conducts his studies at the University of Tennessee's "Body Farm" — a research facility where human bodies are allowed to decompose in a variety of settings.

He still isn't completely sure why dogs are able to track decomposition scents so effectively. But in a recent paper he narrowed it down to a few organic compounds unique to humans that may offer possible explanations.

Mapping the hundreds of unique odours of human decomposition in all its stages could help with cadaver dog training and may even allow technology to replace cadaver dogs one day.

"The problem is only one of sensitivity," Vass said. "Canines, I'm pretty sure, are in the parts per trillion detection range and instruments are only reliable down to parts per billion."

Small number make the grade

Potential cadaver dogs start their training as young as eight weeks old and are usually certified at around two years old.

Breed isn't overly important. The dogs just need to be very energetic and very motivated to work for a reward. However, typical cadaver dog breeds are German shepherds, Malinois and Labrador retrievers.

Only fifteen dogs have qualified to work with the Ottawa Valley Search and Rescue Dog Association in the past 25 years.

Kim Cooper has personally trained five of them.

The most important part of the training is to expose the dogs to as many human remains as possible.

Cooper said human bones can be ordered off the internet from companies with names like Skulls Unlimited and The Bone Room. She occasionally gets access to the surface, be it a piece of carpet or some dirt, for example, on which a body was found.

But the most common training aid is placenta, donated by new moms.

"I'm in the habit of congratulating family members and in the second sentence saying, 'So, what are you doing with your placenta?" said Cooper, who has a few placentas in her freezer at home.

She said a handler will train a dog with the same odour source for approximately six months so the dog learns the subtle changes that take place during decomposition.

"It takes a little while to build up a solid stomach, so that you don't get too disgusted with what you're hauling around anymore," she said.

The pig problem

Mary Cablk of the Desert Research Institute in Reno, Nev., is in the unique position of being both a scientist and a cadaver dog trainer.

She conducted a study on the compounds of human decomposition compared to those of cows, pigs and chickens.

The smell of decomposing pigs was least similar to that of humans, which is a problem for cadaver dog trainers in the U.K., where it's illegal to possess human remains.

They'd been using pigs as training aids for years. But as Cablk points out, "If you have a dog trained on pigs, then you have a dog trained to find dead pigs."

Double blind

Such discoveries have played an important part in the ongoing professionalization of cadaver dog testing and training.

In 2011, Lisa Lit, a researcher at the University of California, Davis, found that what a handler already knows can affect the outcome of their dog's search.

The study was done using dogs trained to find drugs and explosives, but Cablk says the findings divided the cadaver dog community.

If handlers weren't using blind testing (where the handler doesn't know the location of the target scent) or double blind testing (where both the handler and test adjudicator don't know the target) then the dogs could simply be picking up on unconscious cues from the handler, not the scent itself.

"It's one of those things that, to a scientist, it makes perfect sense," Cablk said. "But dog handlers are not scientists."

Over the past five years, training bodies across North America have developed a more scientific approach to training and certification.

Piece of skull

In June, Kim Cooper took her cadaver dogs Breeze and Grief to Massachusetts to get re-certified with the North American Police Work Dog Association.

"We were very excited this year because one of the [training] aids was a piece of skull, so we got to work on a human skull," she said.

"Something new to put into our list of things that we've done."

http://www.cbc.ca/news/technology/cadaver-dogs-science-training-1.3654993
Smithman carrying a child in his arms checked his watch after passing the Smith family and the time was 10:03. Both are still unidentified 9 years later.

Offline mercury

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Re: Poll - Scent Dogs Accuracy
« Reply #363 on: July 25, 2016, 11:23:57 PM »
Very remarkable and very informative, thanks for posting that


Offline Carana

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Re: Poll - Scent Dogs Accuracy
« Reply #364 on: July 26, 2016, 09:47:57 AM »
Very remarkable and very informative, thanks for posting that

I find it interesting as well.

This is one of the reasons why I find it misleading when some people keep referring to "cadaver" odour instead of "human decomposition" odour. Unless that person was congratulating family members on a still-born baby or deceased new mother, the scent is simply decomposing human material that doesn't necessarily mean that someone has died.

But the most common training aid is placenta, donated by new moms.

"I'm in the habit of congratulating family members and in the second sentence saying, 'So, what are you doing with your placenta?" said Cooper, who has a few placentas in her freezer at home.



And handler bias, intentional or unintentional, is an issue in crime scene investigations, particularly high-profile ones. Whether or not that potential bias is exacerbated in independent (as opposed to salaried police) handlers might make for an interesting study.

In 2011, Lisa Lit, a researcher at the University of California, Davis, found that what a handler already knows can affect the outcome of their dog's search.

The study was done using dogs trained to find drugs and explosives, but Cablk says the findings divided the cadaver dog community.

If handlers weren't using blind testing (where the handler doesn't know the location of the target scent) or double blind testing (where both the handler and test adjudicator don't know the target) then the dogs could simply be picking up on unconscious cues from the handler, not the scent itself.

"It's one of those things that, to a scientist, it makes perfect sense," Cablk said. "But dog handlers are not scientists."

Offline Benice

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Re: Poll - Scent Dogs Accuracy
« Reply #365 on: July 26, 2016, 10:35:30 AM »
I find it interesting as well.

This is one of the reasons why I find it misleading when some people keep referring to "cadaver" odour instead of "human decomposition" odour. Unless that person was congratulating family members on a still-born baby or deceased new mother, the scent is simply decomposing human material that doesn't necessarily mean that someone has died.

But the most common training aid is placenta, donated by new moms.

"I'm in the habit of congratulating family members and in the second sentence saying, 'So, what are you doing with your placenta?" said Cooper, who has a few placentas in her freezer at home.



And handler bias, intentional or unintentional, is an issue in crime scene investigations, particularly high-profile ones. Whether or not that potential bias is exacerbated in independent (as opposed to salaried police) handlers might make for an interesting study.

In 2011, Lisa Lit, a researcher at the University of California, Davis, found that what a handler already knows can affect the outcome of their dog's search.

The study was done using dogs trained to find drugs and explosives, but Cablk says the findings divided the cadaver dog community.

If handlers weren't using blind testing (where the handler doesn't know the location of the target scent) or double blind testing (where both the handler and test adjudicator don't know the target) then the dogs could simply be picking up on unconscious cues from the handler, not the scent itself.

"It's one of those things that, to a scientist, it makes perfect sense," Cablk said. "But dog handlers are not scientists."


How true.    IMO no dog handler and his/her dog can be automatically regarded as ' exempt' from this possibility unless they have been previously tested.

IMO it has never been clearly established whether MG was a salaried employee of SYP during his time at PdL - or whether he was being employed as an 'independent' sub-contractor. 

The fact that unlike the other UK police dog handlers he never wore a police uniform and as far as I know was never referred to in any statements as DC Grime - and his dogs were never referred to as 'police' dogs (in the present tense) at the time  -  leads me to believe he was working independently  - and that this was his very first case  -which happened to seamlessly follow on from his departure from SYP.

(From memory so - if I've got an of that wrong - I'm sure someone will point it out)



The notion that innocence prevails over guilt – when there is no evidence to the contrary – is what separates civilization from barbarism.    Unfortunately, there are remains of barbarism among us.    Until very recently, it headed the PJ in Portimão. I hope he was the last one.
                                               Henrique Monteiro, chief editor, Expresso, Portugal

Offline Carana

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Re: Poll - Scent Dogs Accuracy
« Reply #366 on: July 26, 2016, 10:48:08 AM »
How true.    IMO no dog handler and his/her dog can be automatically regarded as ' exempt' from this possibility unless they have been previously tested.

IMO it has never been clearly established whether MG was a salaried employee of SYP during his time at PdL - or whether he was being employed as an 'independent' sub-contractor. 

The fact that unlike the other UK police dog handlers he never wore a police uniform and as far as I know was never referred to in any statements as DC Grime - and his dogs were never referred to as 'police' dogs (in the present tense) at the time  -  leads me to believe he was working independently  - and that this was his very first case  -which happened to seamlessly follow on from his departure from SYP.

(From memory so - if I've got an of that wrong - I'm sure someone will point it out)

There's an unresolved argument as to whether he was still technically on the police payroll or not at the time. Whether he was or he wasn't in that particular search, the fact still remains that his role in Jersey (not long afterwards) was NOT as a police handler, but as someone launching an independent career.

My comment isn't about him in particular, but about anyone embarking on a new career path and who needs positive PR to launch it.

Offline Angelo222

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Re: Poll - Scent Dogs Accuracy
« Reply #367 on: July 27, 2016, 09:18:40 PM »
There's an unresolved argument as to whether he was still technically on the police payroll or not at the time. Whether he was or he wasn't in that particular search, the fact still remains that his role in Jersey (not long afterwards) was NOT as a police handler, but as someone launching an independent career.

My comment isn't about him in particular, but about anyone embarking on a new career path and who needs positive PR to launch it.

There is no argument, the Chief Constable of SYP sent Grime to Portugal, he was not retired at that time.  As for cadaver dogs, it is very true, train a dog using decomposing pigs and he will alert to decomposing pigs.
De troothe has the annoying habit of coming to the surface just when you least expect it!!

Offline mercury

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Re: Poll - Scent Dogs Accuracy
« Reply #368 on: July 28, 2016, 11:34:18 PM »
There is no argument, the Chief Constable of SYP sent Grime to Portugal, he was not retired at that time.  As for cadaver dogs, it is very true, train a dog using decomposing pigs and he will alert to decomposing pigs.

Not in 5a though one hopes

Offline pathfinder73

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Re: Poll - Scent Dogs Accuracy
« Reply #369 on: July 31, 2016, 11:02:44 AM »
There is no argument, the Chief Constable of SYP sent Grime to Portugal, he was not retired at that time.  As for cadaver dogs, it is very true, train a dog using decomposing pigs and he will alert to decomposing pigs.

All cadaver dogs alert to that medium but this is not a missing pig case.
Smithman carrying a child in his arms checked his watch after passing the Smith family and the time was 10:03. Both are still unidentified 9 years later.

Offline Carana

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Re: Poll - Scent Dogs Accuracy
« Reply #370 on: August 01, 2016, 10:35:39 AM »
There is no argument, the Chief Constable of SYP sent Grime to Portugal, he was not retired at that time.  As for cadaver dogs, it is very true, train a dog using decomposing pigs and he will alert to decomposing pigs.

I haven't found anything that would confirm that the chief constable of SYP sent him to Portugal. Where did you read that?

ASAIK, it was Mark Harrison (of NPIA at the time) who proposed Grime's services to the PJ.

Offline mercury

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Re: Poll - Scent Dogs Accuracy
« Reply #371 on: August 03, 2016, 12:32:00 AM »
I haven't found anything that would confirm that the chief constable of SYP sent him to Portugal. Where did you read that?

ASAIK, it was Mark Harrison (of NPIA at the time) who proposed Grime's services to the PJ.

hardly relevant, if anythng MHs recommendation would have carried more weight

Offline Carana

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Re: Poll - Scent Dogs Accuracy
« Reply #372 on: August 03, 2016, 06:22:37 AM »
hardly relevant, if anythng MHs recommendation would have carried more weight

Not relevant to what?

Offline pathfinder73

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Re: Poll - Scent Dogs Accuracy
« Reply #373 on: August 03, 2016, 07:56:25 PM »
Wednesday night, investigators, acting on a tip, descended on the building - one where the missing woman's husband had done some construction work. Inside, they found a wall that stood out from the others. A dog trained to detect cadavers became excited when he got near the wall, police said.

Yesterday morning, police were back in force.

By mid-afternoon, investigators knocked down the wall and removed a concrete block about 3 feet wide and about waist-high from a cubbyhole. They then called in firefighters, who cracked open the concrete with jackhammers and heavy blades and found the decomposing corpse inside.

The body was wrapped in duct tape and was covered with plastic and a canvas painter's tarp. The wrapped body had been encased in concrete, cinder block and construction debris.

"The body is wrapped up - can't identify if it's male or female, age, nothing," Bernardi said.

http://articles.philly.com/2001-08-17/news/25299231_1_investigators-dental-records-concrete-block
Smithman carrying a child in his arms checked his watch after passing the Smith family and the time was 10:03. Both are still unidentified 9 years later.

Offline mercury

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Re: Poll - Scent Dogs Accuracy
« Reply #374 on: August 04, 2016, 12:14:39 AM »
Not relevant to what?

SY were not involved and even if they were MH would have the say