The Evidence in Blood and Urine Samples

The Evidence in Blood and Urine Samples

A thorough defense by an Orange County DUI attorney will challenge all the evidence in the prosecution’s case against you. Whether a sample of blood or urine was collected from you, there is a specific protocol that must be followed by law enforcement at each stage of the procedure. If not, your attorney may be able to create a reasonable doubt as to the test results.Orange County DUI attorney

The first consideration is the split. It is essential to obtain a portion of whatever sample was collected from you. Your attorney will have this analyzed by an independent laboratory and compare the result with what the government’s lab came up with.


For the prosecution to be able to admit the test results of the sample obtained from you it must establish a chain of custody that demonstrates the manner in which the sample was taken and how it was cared for. For instance:

Who drew the sample?

What are that person’s qualifications?

When and where the sample was taken?

Under what circumstances was the sample collected?

Which lab technician analyzed the sample, and what are his or her qualifications?

Each time the sample changes hands, a document must be signed and dated to ensure it is accounted for at all times.


Additional issues involve testing. The test employed must be one commonly accepted in the field, but it also must be done in a precise manner. Equipment must be maintained properly, other samples must not be commingled which could contaminate the result, and the actual vial your sample is stored in must meet certain criteria. The overall rating of the laboratory conducting the test is also a factor to be reviewed by an experienced Orange County DUI attorney. For a free evaluation of your case, please contact Mike Coffey.