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What Is A Motion In Limine Or A Motion To Suppress Evidence In A DUI Case?


A motion in limine and a motion to suppress evidence in a DUI case are actually two separate types of motions. They are very different. A motion in limine is a motion or usually a list of motions that are brought in when a case is going to jury trial. Most DUI cases do not end up in jury trials, therefore, most DUI cases do not have motions in limine. An in limine motion is basically a motion that sets the rules for a jury trial in California. Some states don’t allow for a jury trial. In California, and specifically in the San Francisco Bay area in Marin County, Sonoma County, Napa County, San Mateo County and some other counties, these motions set the ground rules for a trial. For example, a district attorney or prosecutor, the person who is trying to convict a client of a DUI would be prevented from saying or doing certain things in the trial. The defense also asks the court to prevent prejudicial statements, sayings, and phrases from coming out, as well as certain pieces of evidence that should not be allowed in the case.

The defense will want to make sure that the court and the D.A. are on notice that those things are not going to be coming in, and the court needs to agree to these motions. Sometimes there are just a handful of motions. Sometimes there can be 30, 40, 50 or even more depending on the complexity of the case and the county. Motions in limine can be used to try to keep out someone’s details about their past. That’s something that is often kept out of a trial. As mentioned, keeping a prosecutor from sanctioned things is done with the purpose of trying to keep out certain types of evidence. One of the types of evidence that a prosecutor may try and bring in is character evidence to try to show that a client is a big drinker, a drunk, or has a history of alcohol issues.

Other things that may be kept out under a motion in limine would be anything that might violate a client’s due process rights. A prior criminal record is something that could also be kept out, especially, if they are not testifying or its irrelevant. Other areas that the prosecutor usually tries to bring in is evidence of intolerance. For instance, the prosecutor can say that a person can handle their alcohol, but the legal limit is 0.08, so they should be found guilty because they are over the limit.

Another area that we try to keep out, which most courts let in, is with retrograde extrapolation. Accordingly, we would bring a motion to try and keep the prosecution from being allowed to use their expert witness, and to extrapolate a number that’s on a chemical, breath, or blood test based on average numbers of elimination of alcohol and the average amounts per hour to try to establish an alcohol level at the time of driving. The reason that this is considered junk science is because there are too many factors that need to be plugged into a formula to do this properly.

Some of the best and most famous experts in the world on alcohol absorption and elimination say that without having all of the factors, you cannot predict what somebody’s alcohol level would have been hours before the actual test. To try and find, you would need to know what the alcohol level was at the time of driving, how much alcohol was present in the drink or drinks, when they had the drink or drinks, the overall period of time, food, and temperature. You have to make too many assumptions to make it an accurate science; to make it anything more than just a guess.

That’s why we try very hard to keep that out, but unfortunately, most courts will let it be admissible. So, it’s the attorney’s job to make sure that the jury understands that it is junk science, and that if you don’t have all of the factors for retrograde extrapolation in all the pieces needed, then you can’t have accurate numbers. Those are the types of things that call for a motion in limine.

A motion to suppress is different. A motion to suppress is typically brought before a jury trial where the defense would say that due to insufficient cause to arrest someone for a DUI, all of the evidence should be tossed out. Usually, with a motion to suppress, it would be a situation where you get a video of the driver driving and getting pulled over for a bunch of reasons that the arresting officer puts in a police report. When the defense gets the video and sees it, they can determine that the person was not actually weaving over the line. They may have weaved in their lane once or twice and touched the line, but they did not go over the line and almost hit the car in the next lane like the officer said in his or her report.

Showing that the officer did not have a proper reason to pull the driver over may be a reason for a court to determine that it is not a good stop nor a good arrest. Moreover, everything that happened after the driving such as statements, field testing, blood and/or breath tests could be suppressed or thrown out. That result would gut the prosecutor’s case, and the case usually ends up getting dismissed. Other types of suppression motions can involve a medical issue such as with a blood draw. There may have been a situation where the medical procedures that were used to draw the blood did not comply. Therefore, the blood draw should be thrown out. In situations like that, the evidence of driving and field sobriety testing that happen before the blood draw, would most likely still come in.

But, if what they call accepted medical practices or AMP is violated, then the blood results may not come in, and they may not have a number at or over a 0.08% charge to go after someone. They might just have the impairment charge, and that might cause the D.A.’s office to drop or dismiss the case, or offer a reduced charge. It usually makes it easier to have a better chance at winning the case at jury trial. Consequently, having a motion like that with an accepted medical practice, the defense could bring in an expert in that field. An example or an expert could be a nurse or someone who can testify about that type of situation. Experts are expensive, but it is worth it if you can keep blood results out while they testify about the conditions.

For instance, there was a case where the conditions were really bad. There was a blood test done in a holding area where there was a toilet and drain, and the conditions were very scummy. You usually don’t see that, and it was pretty overwhelming, but it allowed the judge to see the circumstances and suppress or keep the blood results out.

For more information on Motion In Limine & Motion To Suppress Evidence, a FREE case evaluation is your next best step. Get the information and legal answers you are seeking by calling (415) 523-7878 today.

Aaron Bortel

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