Breathalyzers are an important device used in DUI cases. Since there are so many DUIs over the course of a year in all of the jurisdictions throughout the Commonwealth, the Department of Forensic Science manages and maintains these machines.
In the course of the last forty years, DUI defense attorneys have tried various ways to discredit breathalyzers. Whenever they are successful, the Department of Forensic Science responds by changing their procedure to make them comply and more reliable.
Once they are admitted as evidence, the judges and juries give them good weight, and they often tend to be a basis for conviction. However, an experienced Alexandria DUI attorney can still bring up the inaccuracies that may manifest from breathalyzer tests in a defense for a client.
Breathalyzer machines are normally accurate. As they are maintained by the Department of Forensic Science, they are constantly being tested and calibrated to ensure they are always functioning properly. As the Department is always updating procedure and improving accuracy, they are given great weight in Alexandria DUI cases by the judge and juries.
The breathalyzer produces results. If everything was done appropriately by police, which typically it is, that result comes into evidence. It is always admissible evidence if it was done correctly. The judge can make a permissive inference that the reading on the breath machine relates back to the time the person was driving.
If they registered a 0.08 at the time they blew into the machine, the judge can infer that they were at level 0.08 at the time they were driving. This is done in every case in which there is a result, and it is given much weight.
One common way to have a false positive or inaccurately high Blood Alcohol Content score is if you have mouth alcohol. The breath machine is supposed to be analyzing the amount of alcohol in your blood, not in your mouth. If you burp or belch alcohol from your stomach into your mouth and then blow into the machine, that can increase the reading. This is one way that you can have a false positive, or at least a rating that is higher than it should be.
There are many different defenses such as these which can cause artificially high readings, like having a high temperature in your mouth, or if the room has a lot of ambient alcohol, which means there is alcohol in the room with the testing machine. Sometimes it is possible to show that the machine has not been kept appropriately, been recently maintained, or been calibrated properly. Any of those things can lead to artificially high ratings, as well.
Breathalyzers are used daily in every jurisdiction. Typically, they are kept in a room approved by the Department of Forensic Science to ensure that ambient alcohol, or alcohol in the air, does not get into the machine and become stored in the machine’s temperature. They are calibrated every six months, and records of each calibration are kept. The logs are obtainable in any single case to make sure that everything has been calibrated appropriately.
The Department also runs diagnostics on the machines, fixes any problems they have, and then calibrates them every time a machine has been repaired. As everything that the Department of Forensic Science does on the machines are logged, they are given a lot of weight in court.
A common misconception about breathalyzer tests in Alexandria is the weight they are given in court. The judge and jury both take them very seriously, and it can be very difficult to refute the results of a breathalyzer. Another misconception about breathalyzer machines is that they tend to be erroneous, or at least provably wrong.
If a person does have a blood alcohol reading, then they can expect it to be very hard to discredit, though a DUI attorney experienced in Alexandria cases may be able to help shine doubt on the test results.
Any erroneous breathalyzer result can be challenged in court, but there must be proof as to why they are wrong. There must either be some flaw with the machine, or an occurrence while being tested that would result in an error. It must then be followed with reasoning as to why it is believed to be incorrect. There are various ways an Alexandria DUI attorney can challenge the results of a breathalyzer test. Which method will work for a case varies on a case by case basis.
The person faced with the DUI can call in their own expert, who can then be cross-examined; the machine can also be proven wrong based upon other observable facts, such as lack of noticeable impairment in the person. However, while there are various ways to attempt to discredit the breathalyzer machine, it can be very difficult to do. It does not happen very frequently, but they can be discredited.
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