An attorney who specializes in DUI / DWI defense does a great deal of work before a case ever gets to trial. He or she likely will make one or more pretrial motions before taking the case to trial. One such motion is a request to have a blood or urine sample split to enable independent testing by a forensic expert.
Anyone arrested on suspicion of drunk driving or driving under the influence of drugs (DUID) must be told of his or her right to have a blood or urine sample preserved for later re-testing of the blood alcohol content (BAC). This is especially important when a driver submits to a breath test, because when one is taken, there is no independent sample retained for later retesting.
The chemical test can be a significant piece of evidence used against the defendant in court. The prosecution will attempt to use a chemical test result of .08 percent or more “the legal limit for driving” to prove a defendant is guilty of drinking and driving. However, many chemical tests are given an hour or more after the driver was pulled over. It’s not illegal to have a BAC of .08 percent at the police station, only when driving a vehicle. An independent expert may establish that the driver’s BAC at the time of driving was not above the legal limit.
Once the sample has been obtained, it is sent to a private, independent forensic toxicologist for testing. The agency which took the sample in the first place is mandated to collect a sufficient amount in order to permit enough of a split to be utilized in future tests. Testing will analyze not only the blood alcohol content of the sample, but also whether the testing procedures were strictly followed.
Regulations mandate strict guidelines on proper collection methods. Blood samples must be collected using sterile, dry hypodermic needles and syringes, or using clean, dry vacuum type containers with sterile needles. No alcohol or other volatile organic solvent can be used to clean the skin from where the specimen was taken or to clean the equipment used in the collection. Additionally, the blood shall be mixed with an anticoagulant and a preservative. If the levels of the anticoagulant and preservative are not at the proper levels, the results of the tests may be invalid. For example, if the blood sample becomes fermented, it will produce falsely high BAC readings.
Sometimes the original blood or urine sample is lost or destroyed. While the law does not impose a duty on the prosecution to collect evidence that might be beneficial to the defense, once collected, a duty is imposed to preserve this possibly exculpatory evidence – evidence that may point to the defendant’s innocence. If the prosecution has failed to preserve such evidence, a savvy drunk driving lawyer can move for sanctions, which may result in the exclusion of the evidence or the dismissal of the case.
If the prosecution fails to comply with an order for a blood or urine split to be utilized for analysis, then again, the defendant can move for sanctions against the prosecutor, and the evidence the prosecutor would have used to convict the defendant may be excluded. If the law enforcement agency has failed to preserve a sample for future analysis, then this will be the basis not only for exclusion, but possible dismissal of the charges.
However, it must be proved that the prosecutor or law enforcement agency acted in bad faith. If no bad faith can be established, then the defendant is entitled to relief only on a showing that the evidence was material and exculpatory.
Many accused DUI / DWI drivers believe that a chemical test result that places them over the legal limit for driving means a slam-dunk conviction. However, that’s not always the case. A lawyer who specializes in drunk driving defense can make a motion to have the sample split, send it to an independent laboratory, and create reasonable doubt in the defendant’s guilt.