The Los Angeles DUI Law Blog

Can You Challenge a DUI Blood Test?

You've been busted by police for a DUI, and a blood test came back showing you're over the legal limit. That's the end, right? How can you challenge that?

Actually, there are several potential ways to challenge that kind of evidence. Just because your blood alcohol content tested over 0.08%, the legal limit in California, doesn't mean it's an open and shut case.

We're not saying cases like the Annie Dookhan lab scandal are going to happen all the time. But blood tests are done by people and people make mistakes. You just need to know where to look for them.

Here are a few places you may want to start:

  • Challenge the person taking your blood. The person who draws your blood for the test should be properly qualified to draw blood. That often disqualifies police officers, but that doesn't always stop them from doing the blood draw themselves. There may be other problems with the technician who drew your blood too, so don't be afraid to bring a challenge if something seems wrong.
  • Challenge the chain of custody. Courts are sticklers for procedure, and proper procedure for entering a blood test into evidence relies on the chain of custody. Before using the test results in court, authorities must provide a complete list of who had custody of the sample. If there are gaps in the chain, that opens the possibility that the sample was tampered with and that could lead to the blood test being excluded.
  • Challenge the equipment. Technicians can't just look at your blood sample and see the tequila swimming in there. They use specialized equipment to read the sample and determine your BAC. But just like a Breathalyzer, that equipment needs to be calibrated and maintained to make sure it's working correctly. Bringing a challenge based on improper calibration could just save you.

Of course, more specific challenges may apply to your case and a challenge may not be the right choice in your situation. But if you have an experienced Los Angeles DUI attorney on your side, you'll be in good hands.

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