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Overview of 9 Breath Machine Errors

Welcome back to the DUI Trial Lawyers Academy. This podcast is brought to you by, great lawyers helping great people. And now for your host, sought after speaker, avid mountain bike racer, and renowned DUI trial lawyer, Patrick Silva.
Patrick Silva:
Welcome back to the DUI Trial Lawyers Academy. This is your host DUI trial lawyer, Patrick Silva. Over the next several podcasts episodes, I'm going to be discussing the nine different points of error on a breath machine and how we're going to attack each one of those errors. Right now I'm just going to give you a brief overview of what we're going to be talking about.
The first thing we're going to go into is just the machine margin of error. After that, we're going to be looking at breathing patterns and how that affects the breath machine. Then we're going to be talking about temperature errors. That's going to be the breath temperature. Next, we're going to talk about hematocrit, that's relationship of water in your blood. Then we're going to be talking about partition ratio errors, that is the relationship of the machine and how it's calibrated. We'll follow that up with an examination of mouth alcohol errors, followed up by an examination of extrapolation errors, more errors associated with people with small lungs, and then finally calibration errors.
As I go through these episodes, I'm going to reference articles and I'll actually give you the sites where to find them. PubMed is a valuable resource, I would definitely subscribe to them. I think it costs $35 for an article. If you belong to any type of listserv, you can get these articles. If you email me, I will send you a PDF copy if I have the article and every one of these articles that I'm mentioning, I have copies of.
Let's start off with just talking about the machine margin of error. When a breath machine is being calibrated, usually they're using a solution. It might be something called a "wet bath solution". That's wet bath solution, or a dry gas solution. These are going to be of a known value. Inherently, there's going to be a margin of uncertainty, I'm going to call it a margin of error, of basically 10%. If the machine is being calibrated with a gas or wet bath of a 0.10, then 10% of that is a 0.01. So, that means just inherently on the breath machine by itself, your breath could be plus or minus a 0.01.
Now, let's look at some different scenarios, and I'm going to take California. California, where I practice, we have something called Title 17, that's from the California Code of Regulation. And, what that says is that when a person blows into a breath machine, there has to be a no larger difference of a 0.02 between the two breath results. Well, what does that do for you? Well, one is that you can create a cross-examination pattern where you're cross-examining the lab tech, and you're saying, "Well, look at if the Title 17 is giving you, Mr. Lab Tech, a 0.02 margin between my defendant's breath one and my defendant's breath two, that means that during that breath sequence, that machine could be off or the breath can be off by at least a 0.02. Isn't that right?"
Usually, you'll get an agreement out of that question. If you have a low breath case, let's say a 0.09, .10, 0.08, and you're talking about a Title 17 cross, well, you could say, "Well, Mr. Expert, my client's reading was a 0.08 on his breath one and on his breath two, it was a 0.09. Now, if we're looking at trying to keep those within 0.02 of each other, my client could have blew a 0.06 and that would have been acceptable, or he could have blew a 0.10, and that would have been acceptable. So basically, Mr. Expert, this machine at least starts off with a margin of 0.02."
You got to remember who your audience is. You have 12 people sitting in a jury box who don't have the level of training that you put into, or the preparation you put into, this breadth case. That's a real simple overview of just the breath machine's margin of error. You really want to listen to the next eight episodes where I get really knee deep and deep into the thick of this breath fallacy. And, let's realize it. Breath is guessing what's in your blood. It might be close, but it's still a guess. All right, you know what to do. Put on the boxing gloves, climb in the ring, have a great fight. Over and out, bye.

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