Demolishing the State's Test Results
Through Cross-Examination

Note: the following lecture was presented by Mr. Taylor in 1997 at a national seminar in New Orleans entitled "Mastering Scientific Evidence in DUI/DWI Cases."

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"95%?" I'd say, you know, you narrow, you get him down. No expert is going to claim 100%. They lose credibility. The worst will say 99%. Okay 99%. Now John drops it and come time for argument to the jury, he brings in a clear plastic bottle of aspirins. And he tells the jury, "Ladies and gentlemen, in this bottle are 100 tablets. 99 of the tablets are aspirin. One is strychnine. If you had a headache...."

All right. "The Defective Warranty." I claim this one. Read these manuals. You—get a manual. Get it through discovery. Get court orders. Whatever you have to do. Get the manuals. Pay the Xerox costs if they're not going to turn the original over to you. Get the operator's manuals, get the supervisors or technicians manuals, if you can and read them. Don't just read the obvious stuff. Read the not so obvious stuff.

A couple [of] years ago I was reading through and I was looking at this page and there was just very, you know, this boilerplate warranty. With the fancy borders and the whole thing and it had the standard boilerplate warranty and I thought to myself, okay I'll read it. And I read it and it had all the standard stuff. It had, for example, the following language halfway through it: "There are no other warranties, expressed or implied, including but not limited to, any implied warranties of merchantability or fitness for a particular purpose."

The manufacturers of the Intoxilyzer 5000 do not warrant this machine to be fit for testing blood-alcohol on the breath?!

I've had a lot of fun with this warranty on cross-examination with various experts. "Mr. Jones, do you have a toaster? Does that $19 toaster have a warranty?"

"Yeah, I think so."

"Is that $19.95 toaster warranted to toast bread?"

"Yeah, I think so."

Go on. "Repaired components are warranted for a period of 90 days from the date of repair and that warranty is subject to the same limitations as this warranty." In other words, if this machine falls apart, when it falls apart, we've got to patch it back up again. It's only good for three months.

"Mr. Jones, how long is that toaster warranty good for?"

"Not longer than 90 days."

Okay, now you've attacked, with some techniques, the general reliability of the machine, the theoretical reliability, the precision. Now you contrast that. You contrast it with the need for precision. You contrast it with, among other things, emphasizing the very tiny invisible amounts of alcohol that this machine is required to analyze. What I call the Invisible Breath Sample approach.

The Intox 5000 captures about 50 ccs of breath. This is equivalent to about one 30th of one cc in the blood. Remember the partition ratio. We're actually testing blood, not breath, except in California. That amounts to about half a drop. Half a drop. If you have a reading of say .20, give them the benefit of the doubt. You got a real high reading. Lots of alcohol involved. You have a .20 reading, that is, the amount of alcohol represented in the blood is one tenth of one percent of half a drop. That is an amount invisible, for all intents and purposes, to the human eye. That is the amount of alcohol that is being analyzed by this machine.

There are visual ways to demonstrate this. One—I forget who I stole this one from, but it is the "55 Gallon Drum" approach. I wouldn't recommend bringing a 55-gallon drum in, but you can use slides or diagrams, or whatever. It just so happens—a happy coincidence—that 55 gallons is roughly the same volume as 210 liters of breath. I'm sure you all recognize that figure. 210 liters of breath. Let's say you got a .20 reading again. You get .20 grams of juice or something in a tiny eyedropper or a baby spoon. Something small; a tiny amount. That represents the guilty amount of alcohol in that 55-gallon drum. Now, contrast that with the actual size being analyzed of the breath; 50 ccs.

If that tiny amount of alcohol in the eyedropper is the amount being measured in the 55 gallon drum, imagine how tiny the amount must be if the amount of breath analyzed is only 50 cc's. You have—what you've done is—now let the jury visualize and see concrete examples of what you're talking about.

Point: It requires incredible precision for accuracy in these tests. So how precise are these machines? Close enough for government work, is what I say. Close enough for government work. Inherent error recognized by the worst of experts is one percent. That is .01. They say—they will say—that, "Even if the machine is working absolutely correctly, correctly calibrated, simulator solutions, everything is operating correctly, it still has inherent error of .01%."

That means, let's say we've got a .10, for purposes of easy math. A .10 blood-alcohol. That means it can be a .09 or a .11 and still be operating correctly and accurately in, within that range of inherent error. Well now think about that. We got a range of .02. What percentage is that of the 1 percent, of the .10, it's 20%. There's a 20% fluctuation here. A 20% fluctuation is considered by the State to be scientifically accurate and precise. But, even if everything is working right, it is going to have a 20% fluctuation.

Now in a lot of states, some states, California for example, has sort of codified this further in its regulations and it may require duplicate analysis. Meaning there's got to be two tests—usually 30 seconds apart or so. And the two test results have to be within .02 of each other. If they're not, cop keeps testing and testing and testing until he finally gets two that are within .02 together.