Friday, November 16, 2007

Drug Testing Misunderstood

by blogger jgl

This case really irks me. First off, I'll be the first to admit that mistakes can be made in labs and it is entirely possible for false positives to occur. I will feel extremely bad for this guy if it turns out the lab made a mistake. However, if a mistake does occur, "proving your innocence" through shoddy forensic science is not the right path to take. Pay attention, forensic scientists! This is a classic example of an inappropriate use of forensic science to sway public opinion.

A summary of the case is as follows: Bronco's tailback Travis Henry tested positive for THC (urine). He's "proves" his innocence by taking a lie detector test and having his hair tested for drugs.

Travis Henry has convinced coach Mike Shanahan he's not a pothead. Now he'll take his case to the NFL.

Shanahan said Henry passed a lie detector test and a recent hair sample taken from Henry came back negative for marijuana.

"If the tests were positive, Travis would not be on our football team right now," Shanahan said. "When he went back and took the hair sample and that was negative, the lie detector test and that was negative, we'll let due process take care of itself. If Travis took a test and it was positive, after what he promised me, he wouldn't be on the football team right now."

Mainly because of his attempts to prove his innocence using *science*, his coach and TV personalities (including ESPN's Michael Wilbon and Dan LeBatard) are convinced he is likely telling the truth. I don't expect these guys to know anything about drug testing, but here are the facts:

Lie detectors DO NOT WORK.
Drug testing of hair DOES NOT WORK (for the most part).

Even if hair testing did work all the time, his hair is awfully short (grown in since the last drug test). By taking these bogus tests that scientifically prove nothing, Travis Henry has tricked educated people into jumping on his bandwagon. This demonstrates something most forensic scientists know, *the public often perceives anything scientific as infallible, but can't differentiate between "good" and "bad" science.*

If he really wanted to proclaim his innocence, then he should request that the lab retest his original sample. I don't work in a workplace drug testing lab, but don't they save a portion of samples for some length of time afterwards? Is Henry claiming his sample was mixed up with someone else's? How likely is this? Oh wait, it looks like the lab does have another sample that's already been tested according to this article.

But in a battle that has reached the federal court system, Henry is attempting to block the league from testing the so-called "B-sample" necessary to confirm the positive test, claiming that NFL officials would not allow his expert to be present for the testing of his specimen.

Something doesn't smell right. Plus, I hate to use a non-scientific fact to prove a point, but Henry has tested positive for drugs before (in 2005).


Anonymous said...

Alright, here's what I've been given for information. Urinalysis is very unexact. Reliability and validity ratings arundthe 60% mark. DNA hair testing-90+% on both. I see you're saying something entirely different. Where is a good reference for these statistics?

Anonymous said...

This case is ridiculous and should have been over with back in 2005. I can not call him guilty of using drugs but history is proof that he has used drugs before so it easy for the N.F.L. to point fingers at him. I mean Henry reversed the issue at hand and point fingers at the league for not allowing his expert to be present while he took the urine test. When the test came out positive and Henry stated that he was suing the league should have automatically ordered another test with the expert being present the second time around. A lie detector test???... are you serious... this guy is a professional athlete.. who is not to say he is not a professional liar as well. The lie detector test was a waste. As for the hair samples I do know the exact % of the accuracy of the testing but from what i have researched the results is really determined by the amount of the drug and consistancy of the drug being used. With the urine test i feel it would have been accurate because the urine is full of waste and horomones which is expelled out of the inner body so, it should be able to detect what ever toxin is in the body. TB

Anonymous said...

Travis Henry is not out to set the record straight. He is not suing the league for defamation. Travis Henry is hoping that the NFL will not call his bluff. I pose this question. Why did Henry not take the exact same test again after the results came back positive? It was Henry's decision to change the test method in order to prove his innocence. We can talk forensic statistics all day but research proves that the urinalysis is an effective means for testing traces of drug use. If urinalysis is an inaccurate testing method then why do several organizations beyond the NFL continue to use this method. I'll tell you why...because it's credible. -C.G.

Anonymous said...

This is very interesting to me. First off, why wasn't it mandated that Henry take another urine sample instead of the lie detector and hair analysis? This article has raised a few questions in my mind. How long does marijuana stay in the hair follicles? Well, I researched some articles and found that it is usually 90 days. Some articles also stated that body hair could also be used. Since body hair grows at a slower rate, how long could drugs be detected that way? What was the time peroid between the time he failed the urine test and the time he took the hair analysis? I tried to research this, but I couldn't find anything.I found this to be interesting though, "The NFL, sources said, is contending the rules are clear players can have their own expert present for testing, but the expert cannot be affiliated with a lab or testing service and Henry's expert was affiliated with a lab". (Rocky Mountain News)

Forensic Bloggers said...

great comments.

I believe the first comment is from a non-student and I wish i would have had the time to fully respond earlier. I wanted to find some more sources, but i'll give you what i got.

For urinalysis testing, i'm not sure where the 60% stat comes from, but it is believable. My guess is that the "low" number comes from the fact that some drugs can be in a low concentration in the urine, and are eliminated fairly quickly, depending on the drug and the original amount taken (72 hours ballpark). In this case, all indications are that it was a recent, one time consumption of marijuana that was detected. Urinalysis is good for that.

FOr 90% hair, you mention DNA, which is a different test than drugs in hair, so the 90% could be correct for DNA, but wrong for hair. Or, as with any stats, one guy could have done a test where the conditions favored detection and recovered drugs in 90%. In my quick search, I couldn't find any articles focusing on detecting short term use in hair. All hair articles focus on detection of drugs in chronic users [one example - Skopp, et al. Forensic Sci International 170 (2007)]. This supports the conventional wisdom that hair analysis isn;t good for recent, one-time use.

as for the lie detector, the most comprehensive study on the technique concluded it was junk science (National Research Council "The polygraph and lie detection", 2003). it is. It disgusts me that it is still portrayed in the media (and tv talk shows) as legitimate.

finally, for the last comment, taking another urine test seems like the right thing to do, but after the first positive, surely the THC was out of his system, unless he was a complete idiot and continued its use. And i think he 90 day stat is for chronic users.

finally, with all the criticism of his "legal" actions i would like to state that Henry isn't necessarily a bad guy. I'm sure he's not the first guy to use marijuana near the end (or during) a season. That's fine, but to make the big bucks, you have to play by the rules.

dr. L

Anonymous said...

Hair analysis for substances of abuse is not nearly accurate enough to be used. see

Anonymous said...


מלון [url=]כפר בעיר[/url] - אינטימיות, [url=]שקט[/url] . אנו מציעים שירותי אירוח מיוחדים גם יש במקום שירות חדרים המכיל [url=]אחרוחות רומנטיות[/url] במחירים מיוחדים אשר מוגשות ישירות לחדרכם...

לפרטים אנא לפנות לאתרנו - [url=]כפר בעיר[/url] [url=][img][/img][/url]

wedding dresses said...

bridal online shop bridal gowns wholesale wedding dresses high quality bridal gowns wholesale custom wedding dresses wedding apparel wedding dresses top sellers wedding dresses2010 new arrivals 2010 new arrivals wedding dresses beach wedding dresses Luxury Wedding Dresses plus size wedding dresses wedding party dresses bridesmaid dresses junior bridesmaid dresses flower girl dresses mother of bride dresses wedding shoes wedding bags wedding accessories evening dresses prom dresses cocktail dresses quinceanera dresses little black dresses

buy propecia said...

Hello people want to express my satisfaction with this blog very creative and I really like the views of the focus very good indeed Thank you for the helpful information. I hope you keep up the good work on making your blog a success!

Anonymous said...

If you are planning to try your hand in NFL football betting remember these few tips and enjoy betting.
online betting

• You can probably take the guidance of a professional before you actually hunch forward, online betting exchange is the most effective way you can get along with. You can also trade along with football matches globally.
[url=]football betting[/url]

1. These pre-season games are not played to win. These contests are merely practice scrimmages and try-out sessions for rookies and the team's supporting cast. Think of pre-season games as nothing more than tune-ups for the upcoming regular season. Coaches often do not care very much about the outcomes and do not necessarily call their plays to maximize getting points. Therefore, since the final score is often irrelevant to the teams involved, you should not risk your money on this outcome either.

[url=]bet online[img][/img][/url]

There are 3 different Secondary conditions (i.e., tighteners) that round out this system. Secondary conditions normally exclude only a small percentage of games from the system pool. One example would be to 'Exclude all Monday Night Games', or, in the case of this particular system--games in Week 17 are not included when many of the high-level teams involved are resting players.

Cris said...

This information is very interesting, I really enjoyed, I would like get more information about this, because is very beautiful, thanks for sharing! costa rica investment opportunities

Anonymous said...

Amiable post and this fill someone in on helped me alot in my college assignement. Thank you seeking your information.

Anonymous said...

From there, make sure that when you wager with an online casino that you know exactly what you are doing. The biggest mistake that you could possibly make would be to place bets on games that you are unsure of. For example, if you want to play blackjack at an online casino but do not know how, make sure you get some details first. If you do not, you are doing the equivalent of throwing your money out the window. The bottom line is that you can never win at an online casino if you do not know the rules of the games that you are going to play.
[url=]online casino[/url] casino Lastly you should check the minimum bets for the entire casino site that you are playing with. Just like live casinos, online casinos put minimum bet amounts in place to ensure that they are making enough money off of their patrons. Most of the larger casinos will have small bet amounts that will attract a larger crowd, but some of the smaller sites will have larger amounts, sometimes not affordable to the every once in a while player, to make up for the lack of players.
[url=]online casino[/url] casino Remember also that these sites are not based in the United States, so the national laws that regulate casinos do not apply to this. Keep in mind that since they are outside the country, you might have a hard time on keeping track of them if you ever you were cheated. Remember, distance is daunting if you do not have the means of getting your money back. [url=]casino[/url] casino [url=]casino affiliate program[/url] On each one of these bingo cards, you will find 27 spaces grouped in 9 columns x 3 rows format. Each number is unduplicated; hence, it will not be repeated anywhere else in the sheet. [url=]bingo[/url] [url=]bingo[/url] bingo bingo What you have to do is, coordinate the numbers that are called out by the host with what you have on our sheet, aiming at filling up a pattern reading bingo. The pattern would be announced at the beginning of the game, so you have to be careful to know what pattern you are looking out for. The cards have the b-i-n-g-o letters on rows and numbers running as a column. A host would call out a letter-number combination, which you would have to mark on your sheet. For example if I-34 is called, you will have to look at the I column down to search for number 34. In case you have it, you place a market on it, and so on. [url=]buy phentermine[/url] buy phentermine

Isma said...

Hello .. firstly I would like to send greetings to all readers. After this, I recognize the content so interesting about this article. For me personally I liked all the information. I would like to know of cases like this more often. In my personal experience I might mention a book called Generic Viagra in this book that I mentioned have very interesting topics, and also you have much to do with the main theme of this article.

eco vacations costa rica said...

hello friend amazing and very interesting blog about "Drug Testing Misunderstood" I really would like to have any update about, thanks for sharing this information

Mobile Application said...

My friend recommended to this blog.... you have some awesome articles shear. keep it up the great work

android application | android web application

Anonymous said...

You wrote a very interesting article. And I agree with you. hair loss

Anonymous said...

You wrote a very interesting article. And I agree with you. hair loss Read a useful article about tramadol tramadol

sifs india said...

We provide forensic science training courses and education by online/distance mode with real court cases practice which include analysis of handwriting, fingerprint science, forensic biology, DNA Fingerprinting, Cyber Forensics, ethical hacking, Forensic Graphology,Forensic Psychology.

Anonymous said...

garcinia cambogia extract benefits[/url] is the best obese burning wring available in market now a days. Lose upto 10 kg in 1 month. garcinia cambogia select

Anonymous said...

oZzy moved away ever before, I miss his cock, for always hungry for sex.


Feel free to surf to my site :: hcg injections

Anonymous said...

I am truly pleased to reaԁ thіs website ρoѕtѕ ωhich сonsists of
lots оf valuable facts, thanks for proѵidіng thеse data.

Also visit mу homeρage; mediral hcg drops

SIFS INDIA said...

Thanks for this!!!
SIFS INDIA Experts Opinions and Reports are acceptable in every court in India and abroad (In India- U/S 45 of Indian Evidence Act) and Our Educational Courses Certificates are valid and legal.
SIFS-Investigation Department
2443, Basement, Hudson Lane,Kingsway Camp,Behind GTB Metro Station, Delhi - 110009
Phone : 09953 546 546, 09871 502 343
Email :,
Website :, ,