I am trying to research this issue to get the straight dope, but every piece of information I find seems to be from NORML activists or law enforcement. Does anyone have a link to a good, comprehensive study of not only the results of such sniffs, but of the mechanics of these sniffs and how and what these dogs accurately detect?
For example, do the dogs “alert” for residual drug use? Say I smoked a joint in my car and some time later a dog does a sniff of the exterior. Will the dog alert? What if it was 10 minutes ago? 2 days ago? 10 days ago? 1 year before?
Does it matter if I only smoked one joint or acted like Suge Knight, puffing weed in the vehicle frequently for a long period of time?
Does it matter if I had the interior professionally cleaned? Vacuumed at a car wash? Dumped out the ash tray?
What if I simply bought a dime bag of weed and transported it home (no smoking it in the vehicle). The next day could a dog detect the previous presence of it? The next week? The next year? Five minutes later? Does it matter if my drive home was five minutes, ten minutes, or two hours? What if instead of a dime bag it was a pound of weed? 15 pounds of weed?
Does it make a difference if I opened the bag to get a “test sniff” of it?
My initial inclination is that the police officers who use these drug dogs are well meaning officers who love these dogs, but seem to be married to what amounts to, at least in my initial cursory research, to be junk science that doesn’t belong in court.
That study is a brutal evisceration of the efficacy of a drug dog. Further, it seems to show that it’s not the dog’s fault. It seems that when a handler thinks that there are drugs in a particular location, the dog picks up on the subtle body language of the handler and alerts just to please him.
When I had heard about how the handler could “cue” the dog, I thought the implication was one of illegality on the part of the handler. They are unwittingly influencing the dog who simply wants to please his master.
I recall waiting to pick up my bag from the carousel at LAX one time. Next to me was a young lady, and a drug-sniffing dog seemed very interested in the sweater she was wearing. She said she’d come from Kathmandu, where she’d been in close proximity to some dope smoking.
*The dogs are trained to dig or sit when they smell drugs, which triggers automobile searches. But a Tribune analysis of three years of data for suburban departments found that only 44 percent of those alerts by the dogs led to the discovery of drugs or paraphernalia.
For Hispanic drivers, the success rate was just 27 percent.*
There really isn’t a good way to cover up a scent - see the Mythbusters episodes where they tested a fugitive-tracking dog.
The article is a little weak, because “lack of drugs or paraphernalia” doesn’t mean you didn’t walk through a cloud of dope smoke. Still, the “Clever Hans” effect is probably most of the difference.
A dog that produces a lot of false negatives in training isn’t going to get used for police work.
A dog that produces a lot of false negatives in actual police work, generally will go undetected, since the positive is what results in an actual search.
We get MWD’s in my facility at work sometimes. The handlers will come in before the dogs and hide various drugs or explosives and bring the dogs in. They never fail to find whatever is hidden.
There is a huge difference in ability from dog to dog. A friend of mine is a canine cop who also is a trainer/handler. I was at a competition where ten dogs walked through a serpentine of pylons without signaling, then the eleventh dog found the pylon with a half gram double bagged under it.
I recently listened to a podcast concerning people who helped extricate Jews from Nazi Germany. One operation used false bottoms on boats that ferried Jews out to Sweden. Apparently the Germans got suspicious and starting bringing dogs around to the docks. To counter this, the smugglers made up a concoction of dried rabbit’s blood and cocaine. The dogs were attracted to the blood and then the cocaine dulled their sense of smell. The smuggling continued unabated.
Slightly off-topic: I am reminded of the Milwaukee airport police, who twice hid explosives so well from themselves that their sniffer dogs never found them again.