You look at your DUI paperwork from Fairfield or Vallejo and see a blood alcohol number that feels nothing like your actual level of impairment that night. Maybe you had a couple of drinks with dinner, you felt fine to drive, then you are suddenly staring at a result over the legal limit. It feels like the number must be right because it came from a lab, but something in your gut says it is off.
That reaction is common. People are told that blood tests are the “gold standard” and more accurate than breath tests, so they assume the result is unchallengeable. Almost no one is told what happens to that vial of blood after it leaves your arm, how it is stored in Fairfield or Vallejo facilities, or how a simple refrigeration problem or delay can change the chemistry inside the tube and push the number higher.
At Maas and Russo, we defend DUI cases throughout Solano County, and we do not take blood test results at face value. We request the storage records, chain of custody forms, and lab data that show what really happened to your sample. When we compare those records to accepted forensic standards for refrigeration and preservation, we sometimes see gaps that many attorneys and defendants never notice. Understanding that the technical layer is the first step in deciding how to fight your case.
Why DUI Blood Refrigeration Matters In Fairfield & Vallejo
Blood is not a static substance. It contains cells, proteins, and microorganisms that continue to react and break down after the draw. If a sample from a Fairfield or Vallejo DUI is not preserved and cooled properly, those ongoing processes can change the amount of alcohol in the vial compared to what was actually in your bloodstream on the road. The number on your lab report reflects what was in the vial when the machine tested it, not automatically what was in your body at the time of driving.
In Solano County, prosecutors often rely heavily on blood tests to try to prove DUI charges. Courts tend to see a lab-reported BAC as strong evidence in cases out of Fairfield and Vallejo, where blood is drawn at local hospitals or stations and then shipped to a lab. Many people, including some lawyers, stop their analysis there. They see a number and assume the only issues are whether the officer had a right to stop or arrest you.
We approach these cases differently. Because our practice focuses on criminal defense in Solano County, we see how the evidence is actually handled in Fairfield and Vallejo. We know that the quality of blood evidence depends on storage conditions from the moment of the draw through transport, booking, refrigeration, and testing. When we see unusual BAC results that do not match the client’s description or other evidence, we start asking detailed questions about refrigeration and storage, not just about the traffic stop.
How DUI Blood Samples Are Supposed To Be Collected & Stored
To understand where things can go wrong, it helps to know how the process is supposed to work. In a typical Fairfield or Vallejo DUI case, an officer escorts you to a hospital, clinic, or sometimes a station for a blood draw. A nurse or phlebotomist fills special vials that contain a preservative and an anticoagulant. The preservative, often a compound such as sodium fluoride, is intended to slow down bacterial growth and fermentation. The anticoagulant prevents the blood from clotting, so the sample stays uniform.
Those additives only work correctly if they are present in the right amount for the volume of blood and if the vial is gently inverted several times to mix them thoroughly with the sample. If a vial is underfilled, overfilled, or not mixed well, portions of the blood can be underpreserved, which can matter later if the vial is stored too warm. After the draw, the samples should be labeled clearly, sealed, and documented with the date, time, and who collected them, then placed into the custody of law enforcement.
From there, proper handling requires timely and controlled storage. Accepted forensic practices expect that blood samples will be refrigerated within a reasonable time frame, not left at room temperature for long periods. They should be kept at refrigerator-like temperatures, not in areas that cycle between warm and cool throughout the day. Each movement of the sample, from the hospital in Fairfield or Vallejo to the evidence room and then to the testing lab, should be logged to create a clear chain of custody. When we review DUI cases, we compare what the paperwork shows to these expectations.
What Happens Chemically When Refrigeration Fails
When refrigeration or preservation breaks down, the problem is not just theoretical. Inside that vial, microorganisms that were in the blood at the time of the draw can start to feed on sugars and other substances, especially if the sample is warm. That process, fermentation, can produce additional alcohol over time. It is similar in principle to what happens when fruit juice is left on the counter for days. It begins to ferment and produce alcohol. A blood sample is more controlled, but the same basic chemistry applies when preservatives are not effective, and temperatures are too high.
On the other side, alcohol in a sample can degrade or evaporate, especially if a vial is not sealed properly or if there are temperature swings. Components of the blood can separate, or the sample can partially clot if the anticoagulant is not working correctly. When the lab later tests this uneven or degraded mixture, it may not be measuring a true, uniform sample of whole blood. In some situations, that can cause the testing instrument to overstate the amount of alcohol compared to what was actually in the bloodstream at the time of driving.
Labs commonly use methods such as gas chromatography to measure alcohol in blood. The printout from that machine looks precise, with numbers carried out to multiple decimal places. However, those instruments simply measure what is in the vial at the moment of testing. If fermentation has produced extra alcohol or if the sample has changed in other ways because of poor refrigeration, the machine has no way to correct for that. This is why we focus on the conditions the sample experienced before it ever reached the analyzer, not just the final number.
Common Refrigeration & Storage Failures In Local DUI Cases
In real Fairfield and Vallejo DUI cases, storage defects rarely look dramatic. Instead, they show up as small details buried in paperwork. One common pattern is a long delay between the time of the blood draw and the time the sample is logged into evidence or noted as received at a lab. For example, a draw performed late at night may not be booked until the next morning, raising questions about where and how the vials sat in the meantime and at what temperature.
Transport is another weak point. Blood drawn at a Vallejo hospital might be placed in a transport container for delivery to a central evidence facility or a regional lab. If that container is not cooled properly, or if it sits in a vehicle or office for hours at room temperature, the sample may be warm long enough for fermentation or other changes to begin. Documentation often provides only limited information about transport conditions, which is why we look carefully at times, locations, and who had custody.
Equipment issues can also play a role. Evidence refrigerators in busy agencies may be overloaded or subject to power interruptions. Frequent opening of refrigerator doors can cause temperature fluctuations. Some facilities are supposed to keep temperature logs, but in practice those logs may be incomplete, missing dates, or simply not kept. When we handle DUI cases from Solano County, our local focus gives us a sense of how evidence rooms in Fairfield and Vallejo operate, and we know how to read those small clues on forms that can point to larger storage problems.
Why Faulty Refrigeration Can Inflate Your Reported BAC
For someone facing a DUI, the key question is how these technical problems translate into the number printed on the lab report. When a sample sits warm, and preservatives are not fully effective, microorganisms can create additional alcohol as they ferment the material in the vial. That extra alcohol did not exist in your bloodstream at the time of driving, but the machine reading the vial later has no way to distinguish it. As a result, the reported BAC can be higher than your actual level when you were behind the wheel.
In other cases, separation or partial clotting can cause the portion of the sample drawn into the analyzer to contain a higher concentration of alcohol than the whole blood would if it were uniformly preserved. Even a small shift can matter. A person whose real BAC was in the .06 to .07 range at the time of driving might see a reported result of .09 if storage conditions allowed fermentation or other changes to occur. That difference is the line between being under the legal limit and being over it.
California law is particularly strict about BAC thresholds and repeat offenses. For many drivers, .08 is the key number. For some categories of drivers, such as those in commercial vehicles, the legal limit is lower. Even a small artificial increase caused by faulty refrigeration can move a case from a borderline situation into territory that carries mandatory penalties, longer license suspensions, or harsher treatment for someone with a prior DUI. Our approach at Maas and Russo is to intervene early and look closely at whether the reported BAC truly reflects what the law is supposed to measure.
How We Investigate Blood Test Refrigeration In Fairfield & Vallejo
Challenging blood evidence is not guesswork. We follow a structured process that begins with obtaining every available record related to your sample. That usually includes chain of custody forms, the officer’s reports, booking logs, lab submission forms, and any temperature or maintenance logs that exist for evidence refrigerators. We also request the lab’s underlying data, not just the one-page summary listing a BAC number. These materials show the path your sample took from a Fairfield or Vallejo draw site through the system.
We then compare what the paperwork shows to accepted standards for timing and storage. If the chain of custody indicates that a sample was drawn at a certain time in Vallejo but not booked into evidence until many hours later, we examine where it was in the interim. If an evidence log shows that a Fairfield sample was held at room temperature or in a general locker with no mention of refrigeration, that raises questions. Missing signatures, unexplained time gaps, and vague descriptions of storage locations are all red flags we know to look for.
When the records suggest that storage problems may have affected your sample, we may involve independent forensic professionals to review the lab data or, when possible, to retest a retained portion of the sample. A qualified toxicologist can examine chromatograms and other underlying information to identify signs consistent with fermentation or degradation. Their input helps connect the dots between what the paperwork shows, what the chemistry allows, and what the court should make of the reported BAC. Our familiarity with Solano County procedures helps us ask the right questions and present these findings in a way that judges and prosecutors can understand.
Challenging Compromised Blood Evidence In Your DUI Case
Once we identify specific problems with refrigeration or storage, the next step is turning those defects into legal arguments. In some situations, we may file motions asking the court to exclude the blood test because the state cannot show that the sample was handled in a way that produces reliable results. In other cases, we use the evidence of mishandling to argue that the BAC number should be given little weight, which can affect trial strategy or negotiations with the prosecutor.
Courtroom experience shows that specific, documented issues often carry much more weight than general attacks on lab accuracy. A judge is more likely to take notice when the records from a Fairfield or Vallejo case show that a sample sat unrefrigerated for many hours, or that an evidence refrigerator had documented problems, than when a defense simply speculates that something might have happened. Our goal is to build arguments on the concrete details we uncover in your case.
The impact of these arguments depends on many factors, including your prior record, the rest of the evidence, and how the judge and prosecutor view the case. No lawyer can promise that a refrigeration issue will lead to a dismissal. However, ignoring these issues leaves potentially powerful defenses on the table. By acting quickly, we can move to preserve any remaining sample, secure the records before they are harder to obtain, and integrate storage defects into a broader defense strategy that protects your future as much as possible.
What To Do Now If Your DUI Involves A Blood Test
If your Fairfield or Vallejo DUI involved a blood draw, there are concrete steps you can take now. Start by gathering every document you received, including the temporary license, any hospital or blood draw paperwork, and your citation or charging documents. Note where your blood was drawn, approximately what time it happened, and anything you remember about how long you waited before or after the draw. These details can help us begin to reconstruct the early part of the storage chain.
Next, avoid discussing the specifics of your drinking or the details of your case with anyone other than your attorney. Seemingly casual comments to friends, family, or on social media can end up in the hands of the prosecution. The more important conversation is with a defense team that understands the technical side of blood evidence. The sooner we are involved, the sooner we can request records from Fairfield or Vallejo agencies and labs, and the better chance we have of identifying storage or refrigeration problems before logs or samples are no longer available.
You do not need to become an authority in chemistry or forensic procedures. That is our job. Your job is to reach out quickly so we can use our Solano County experience and detailed approach to evaluate your blood evidence and build a defense that takes every technical weakness into account. If any part of this discussion sounds like it could apply to your case, we encourage you to contact Maas and Russo online or call us at (800) 483-0992 for a focused review of your DUI blood test.