What a DUI Blood Retest Means
A blood result from the state lab can seem final. In fact, many cases keep a portion of the sample, and the defense may ask a separate lab to analyze it. A DUI blood retest is that second analysis.
California law gives people a few ways to get independent testing. Each one has its own conditions.
Retained Samples After a Breath Test
Breath equipment keeps no sample. Vehicle Code section 23614 requires officers to say so and to offer a blood or urine sample that will be kept at no cost. That section also says either party may test the retained sample.
So a person who took a breath test may still have a sample available. The report should note whether one was collected.
Additional Tests at the Person’s Expense
Vehicle Code section 23158 lets the person tested arrange an additional test at his or her own expense. Licensed medical staff or another person of the person’s choosing may administer it.
That section also says failing to obtain an extra test does not prevent use of the officer’s test in evidence. So the extra test is an option, not a requirement.
How a DUI Blood Retest Usually Works
A defense lawyer usually handles the request. The steps tend to follow a pattern.
- Confirm a sample exists and where it is stored
- Ask the court or lab to release a portion
- Choose an accredited laboratory
- Arrange transport with a documented chain of custody
- Receive and review the result
The second result can agree with the first, differ slightly or differ a lot. Each outcome means something different. A close match tends to support the original number, while a wide gap invites questions about storage, method or the lab itself.
Costs and Timing
The person usually pays for an independent analysis. Prices vary, and no general article can quote them. Ask the lab for a written quote before agreeing to anything. Timing also matters, because a sample may degrade or a lab may discard it after a set period.
So early contact with a lawyer helps. The guide on DUI blood sample handling explains the storage records worth checking first.
Using the Results
Once the result arrives, the lawyer decides how to use it. A DUI blood retest result does not replace the state lab result. Instead it gives the defense another data point. An expert can explain any difference and what might cause it.
The article on DUI forensic expert reviews covers how such an expert works. For the DMV track, timing is tighter, as the guide on DMV DUI hearing evidence explains.