Can you beat a DWI case if they took your blood? The answer is yes. We do it all the time.
A lot of people arrested for DWI in Friendswood and the rest of Galveston County assume a blood result is the end of the story. It isn't. A blood case has several places where it can fall apart, and we look at every one of them in order. Here's how.
Step one: was the traffic stop justified?
If we're trying to beat a DWI blood case, the best way to do it is to get all of the evidence of the blood test excluded. The first thing we look at is the traffic stop.
Did the officer say you were weaving within your lane? Maybe even leaving the lane, but not in a dangerous way? Those are some of the best ways to get a traffic stop suppressed. And if the stop is suppressed, all the evidence after it gets suppressed too, the blood included.
Step two: was your consent really consent?
If you consented to a blood draw, we look at whether that consent was coerced or forced.
Officers are supposed to read you a document called the DIC-24. It starts off saying you're under arrest for an offense involving acts alleged to have occurred while operating a motor vehicle or a watercraft while intoxicated. You can actually also get arrested for flying or operating an amusement park ride while intoxicated, though those aren't listed on the DIC-24. I'm not sure why.
They're supposed to read you that document. If they don't, or they do but then threaten you in some other way, they could coerce that consent for the breath or blood test, and we could get that result suppressed.
Step three: the four corners of the search warrant
Say you refused to give a breath or blood test, and the officer went to a judge and got a search warrant for your blood. They may not have included everything they needed in that warrant.
There's a principle that says we look only at the four corners of the search warrant. No additional information, even if the officer knew it, gets read into it. If there wasn't probable cause in the warrant, even though a judge signed it and they got your blood, a judge later on, maybe a different judge, can suppress that evidence.
Those are the first things we look at: the stop, the consent, and the warrant.
Step four: how they actually tested your blood
If the case is headed to trial, because we can't work out an agreement that works with our client's job, life plans and career plans, and we can't get the blood suppressed, then we look for errors in how they tested the blood.
A lot of people don't know this: they don't actually test your blood. They test the air above your blood while it's sealed in a vial. Something called Henry's law says the alcohol concentration in the air above the blood and in the liquid below will equal out.
They use a machine called a gas chromatograph. It looks like a little computer, and in real life they're not testing one sample at a time. They're testing something like 50 samples at a time. Ask a lab analyst how many times they've messed up a sample, and they're never going to admit to swapping samples. I'm sure it happens at least sometimes.
Here's how it works. A carrier gas is pushed through a flow and pressure regulator and into a column, which is just a tube wound up in a coil, and on to a detector. Your sample of air gets injected into the column along with the carrier gas. They calibrate the machine with a known sample of alcohol, so they know how long it takes alcohol to come through the column. Then they inject your sample, look at what came out at that time, and the computer reports what they think the alcohol result is.
There are a lot of things that can go wrong. The column may not be operating properly. There can be carryover, residual alcohol left in the machine from one sample to the next. If the person ahead of you had a high result and you were a 0.06, did carryover of 0.02 bump you up to a 0.08?
So we look at the computer data. Is the instrument recording all zeros when nothing is supposed to be coming through? Is there residual carryover? Is a sample before or after yours having problems? When did this instrument last go down? Whoever runs the testing, the Department of Public Safety, the Houston crime lab, the Galveston crime lab, has to keep meticulous records on these machines. If we find a problem in the way the testing was done, we can win a trial or negotiate a better plea.
Step five: pretrial diversion
If we can't get the case dismissed outright, we look at a pretrial diversion. It's a type of probation where the case is dismissed at the end and can be expunged off your record.
Don't confuse that with deferred adjudication or straight probation. Those avoid jail time, and they technically avoid what's called a conviction, but they can still be used to enhance a future DWI to a second or a third. And even with a non-disclosure, government agencies and the police are always going to see it. Pretrial diversion is the way to avoid that.
To get there, we build mitigation evidence, the kind of evidence that shows our client is worthy of a second shot at a clean record: letters of recommendation, classes, and treatment.
Every case has a best result
Not every case ends in a full dismissal. But every case has a best result based on its evidence, and we get there through an individual case analysis. In a DWI, the most important thing is normally the video. Then we move to the blood and breath tests, and then to the mitigation evidence. Every case is different, and we pay attention to each of those phases.
This post is for educational purposes only and is not legal advice.