I have a friend who 2 months ago was early-released from prison after serving four years of a five-year sentence for drug dealing. We’re very good friends and I’ve known him for several years, from before he went in. Since his release, he’s bought a truck and gotten a great job, and everything totally seems to be on the up and up.
As part of his probation, he occasionally has to take a urine drug test at random. Last week, he was notified that he had come up positive for cocaine. No problem, we thought, he’ll get a retest and everything will be okay.
Tonight the retest came back positive. He swears up and down he hasn’t used. He knows that if I knew he was back into drugs I’d never speak to him again. We’re not lovers or anything, just very good friends and I’ve been very supportive of him. It’s hard to say if I would even notice if he was using again, as I don’t have much experience with the harder drugs.
What the hell? How can TWO tests come back false-positive?? I just don’t know what to think. He’s now planning on getting a hair-follicle test on his own to prove his innocence.
Anybody ever had this happen? Anybody know HOW this could happen? I want to believe, I do… but I just don’t know.
You’ve already said it but I was going to suggest that he get a drug test on his own from a third part testing facility. Other then that google around and see if something may be causing a false posative. Is he on ANY medications AT ALL, wheather RX or OTC?
He was taking Cephalexin (Keflex) for a staph infection, and he takes a multivitamin. Some history: I dated this guy way back when, for a couple of years, then he got into crystal meth and I broke up with him. He then began dealing and a couple of years later got busted. We were always (except for the couple of years between me breaking up with him and him getting pinched) very good friends. While I never considered him a potential husband, I’ve always trusted him implicitly and considered him one of my best friends. Since his release, he has been rock-solid and even as just a friend (without benefits), treats me a damn sight better than most men I’ve been involved with.
I’m not naive, by far, and I can’t even believe that I’m kind of buying this whole thing. Wow. One side says, “oh yeahright, you know he’s getting high.” The other side says “I don’t think so.”
It’s just so bizarre.
I’d say its possible to get two false positives but not very likely. It is a lot more likely that he is using again.
I was gonna say something like two false positives should equal a negative…but obviously this is a serious post and should probably be in GQ.
A friend of mine had the same thing happen awhile back. He works in the Texas prison system as a guard and is subject to random drug testing. Well…you know what happened. Miles and miles of bullshit later they decide that he had been prescribed a codeine based cough syrup and that it sent up the red flags that started the whole mess. He had saved the bottle and recently (when the test was done) had been fighting a little cold.
Now I’m not a doctor and I couldn’t swear to any of this, but from my understanding there are several things that CAN show up in a urinalysis or a blood test as drugs which might be due to something else.
Urban myth? maybe…but my friends case wasn’t a myth. There are also a lot of prescription drugs out there and some “new” stuff folks are now taking that is supposedly legal and yet works like speed.
It’s basically a simple math question. The problem is finding honest and accurate appraisals of the probabilities of false positives, false negatives, and the rate of use in the target population.
For example, based on some info I gathered a few years ago, in a random employment drug screening, a positive result implies that the subject most likely didn’t do drugs. I don’t recall the specific numbers, unfortunately, so I can’t help much beyond saying that I’d be very suspicious of any positive result.
Considering your target population, felon drug dealers, two positive results implies that he’s probably not telling you the truth. I would concur with the posters above who advised a third-party independent test.
Shoot, I missed part of the OP.
Go here: www.ai.mit.edu/~murphyk/Bayes/bayesrule.html
That’s some of the math behind the problem. The fact is that there are just errors. It’s simply a fact of life, completely independent of whether medications or foods can mimic various drugs. For example, in the only double-blind test of DNA labs that I’ve heard of finds the chances of a false positive to be one-in-a-hundred, or something like that. The labs, employers, and cops want you to think that just because urine/drug tests are “scientific” they are the end-all be-all. That’s simply not true.
Take the case of DNA. I just moved out of a village of 1,500 people. Suppose there was a rape and DNA evidence was all they had. If the tested all the men, say 750 men, you’d expect to see seven or eight people test positive. So, based solely on a random draw, a DNA match doesn’t mean much at all.
With O.J., as with your friend, things are different. There isn’t a random draw. O.J. was a wife-beater who’s former wife was murdered. Because of this information, the positive match becomes much more meaningful. Ditto for your friend. As a former meth user and dealer, among other things, two positive tests are far more incriminating because he probably isn’t in a population of people where drug use is unusual.
Hope that helps.
For more info, I still recommend, as I’ve done in about a hundred threads, Gerd Gigarenzers’s book Calculated Risks.
A one percent false postive rate in DNA testing, which is reputed to have accuracy levels many orders of magnitude beyond that is amazing. Do you have some cite for this extraordinary claim.
Gerd Gigerenzer 's book Calculated Risks.
Here’s his CV: www.mpib-berlin.mpg.de/en/mitarbeiter/cv/gigerenzer-body.htm
Poppy seed rolls?
Based on his history and the results of two tests I think you already know the real answer. Addicts do what they need to do to protect their habit. Spoken from experience.
Not for cocaine. Opiates, perhaps. Poppy seeds are from a poppy plant, but not the same plant as the opium poppy. There are minute amounts of opioids in poppy seeds, though.
Didn’t read closely. Sorry.
The accuracy is many orders of magnitude beyond that if the testing is perfectly conducted.
But I always wondered what was the likehood of a DNA testing not being properly conducted and resulting in a false incriminating result (I don’t how exactly they are done, but for instance, let’s assume that both compared samples are contamined by the DNA of a third person. Say, the DNA of one of the lab techs. Or the samples are mixed up and the lab test twice the same one. Both scenarios implies that both samples are tested for comparison in the same place, but I don’t know what are the procedures. And there are most probably many other possible scenarios).
In other words, the theorical accuracy of a DNA comparison might be many orders of magnitude higher than its actual, practical accuracy, due to the risk of human mistakes. Not even mentionning someone deliberatly messing them up.
If I, for once, was accused of some heinous crime and a DNA test was proposed, given that their results are now considered as essentially undisputable evidences of guilt (or innocence), I sure as hell wouldn’t give my consent to it before being told exactly what procedure will be followed (though the police wouldn’t care. In one case of criminal investigation for a kid’s murder, the whole male population of a small town was tested. One guy refused, and they just got a warrant and took his hairbrush or somesuch. He was cleared by the test, by the way).
Still, I would be warry of DNA tests. I wouldn’t like the idea that me spending or not the rest of my life in jail is dependant on a number of guys in the police and in the labs doing their job properly.
I anybody knows how reliable DNA testing is generally considered to be practically, I would be interested to know.
Where there’s human involvement there can be human error. I watched a fascinating TV program the other day about a lab in Texas that made huge mistakes when interpreting DNA results that ended with more than one person being locked up based on faulty evidence.
That said in this case I think he’s lying. He doesn’t want to lose you as a friend but he can’t stay away from the coke. Been there, done that.
Good luck. Sounds like a sticky situation however it turns out.
Apart from ordinary human error there have been reports over the last few years about antibiotics producing false cocaine and heroin positives. Here are some warnings and here is another mention.
As a former worker with substance abusers I can see that it is very likely that he has fallen back on old behaviour patterns, but the fact he is taking Keflex makes me wonder. I can see someone talking up their innocence and threatening a hair test but if he is actually willing to take it I suspect he may come out clean.
Has he been to the dentist? Novocaine might give a false positive.
I meant to add that the second sample is largely a joke. It always comes back the same as the first one - just look at sports people, no one is ever cleared by the second sample. They are the same sample split so in all likelihood if one is contaminated so is the other. If they are mislabelled it doesn’t matter if you have 10 samples. Even in several reported instances of laboratory contamination, multiple samples have been contaminated.