Breath/Blood Testing in Drunken Driving Cases

Understanding the intricacies of blood and breath testing methods is crucial when defending yourself against drunk driving charges. These tests play a significant role in DUI cases and often determine whether there’s sufficient evidence to prove whether a driver was under the influence of alcohol or drugs. This article explores various testing methods used in the U.S., their implications in DUI cases, and how defense lawyers can challenge test results.

This article is a comprehensive guide to various breath and blood testing methods. However, DUI laws vary by state. If you have been charged with a DUI and want the most up-to-date information on DUI blood and breath tests, talk to a local DUI defense lawyer. Laws vary by state. A local and experienced drunk driving defense attorney will be best positioned to provide legal advice and, if appropriate, representation.

Why Do You Have to Take a Breath or Blood Test?

You must submit for a breath or blood test because you consented to these chemical tests when you got your driver’s license. Under state implied consent laws, drivers give their consent to DUI breath, blood, and urine tests when arrested for drunk driving. This is a condition of being able to drive in your state. Refusing a DUI blood test or breathalyzer test comes with penalties. In some states, you can face criminal charges for refusal.

Evidence of refusal can be used against you in court, and most states allow juries to draw an adverse influence from drivers who refused a chemical test after a DUI arrest. Refusing a chemical test can result in license suspension and other penalties. 

In severe drunk driving cases, the police can get a warrant to force you to submit to a breath or blood test. This includes drunk driving injury accidents that can result in felony charges. Law enforcement officers can get a warrant from a judge and draw blood by force.

Blood Tests 

A blood test measures the blood alcohol concentration (BAC) in the driver’s blood by analyzing a blood sample taken from a driver. Experts consider this method highly accurate, so prosecutors often use it when breath tests are inconclusive or impossible. Police officers or medical personnel usually collect the blood samples at the police station or medical facility. They then send the sample to a lab for analysis to determine the BAC. 

Blood alcohol concentration (BAC) tests measure the amount of alcohol in a person’s bloodstream. The legal limit for BAC in most states is 0.08%. Exceeding this limit can result in DUI charges.  Any errors in handling the blood sample or delays in testing can lead to inaccuracies.

Breath Tests 

A breath test measures the amount of alcohol in a driver’s breath. Law enforcement uses breathalyzers and other breath testing devices, often on the side of the road during a traffic stop, to estimate BAC quickly and non-invasively. The breathalyzer test is the most common form of breath testing. A police officer instructs the driver to blow into the device, which then calculates the BAC based on the breath sample provided. Police must calibrate and fine-tune breath testing devices regularly to ensure accuracy. Incorrect calibration can lead to false results.

The preliminary alcohol screening (PAS) test is a portable breath test police use during DUI investigations to establish probable cause for a DUI arrest. While the results are not always admissible in court, they help law enforcement determine if further testing is necessary.

Urine Tests 

A urine test measures the amount of alcohol or drugs in a driver’s system. It is less common than blood or breath tests but can be used when these methods are unavailable. The police collect a urine sample and send it to a lab for analysis. The results can indicate recent alcohol or drug use but are less reliable for determining current impairment.

A criminal defense lawyer can challenge urine test results based on the accuracy of the collection and testing process. Factors such as contamination and the time of driving can impact the results. These tests detect the presence of drugs such as marijuana, cocaine, opiates, methamphetamine, amphetamines, PCP, benzodiazepine, barbiturates, methadone, tricyclic antidepressants, ecstasy, and oxycodone.

The DUI Investigation Process 

The DUI investigation begins with a traffic stop and can end in court. Understanding each step, from the initial police officer interaction to presenting evidence in court, is vital for building a solid defense. 

Law enforcement officers conduct DUI investigations, administer field sobriety tests, and perform breathalyzer tests. They must follow strict procedures to ensure the validity of the test results. Before conducting a chemical test, officers must establish probable cause for a DUI arrest. This can include observations of impaired driving, failed field sobriety tests, or a PAS test indicating alcohol consumption. 

Test results, police reports, and witness testimony are evidence in DUI cases. A defense lawyer must scrutinize this evidence to identify weaknesses in the prosecution’s case. 

In most states, the legal limit for BAC is 0.08%. Exceeding this limit can lead to severe penalties, including license suspension, fines, and imprisonment. Several factors can affect BAC, including the amount of alcohol consumed, the time elapsed since drinking, the driver’s body weight, and the driver’s metabolism. These variables can impact the accuracy of BAC tests. 

Accurate testing is crucial for ensuring fairness in DUI cases. Inaccurate test results can lead to wrongful convictions and unjust penalties. 

The DUI Defense Lawyer 

DUI lawyers use various strategies to defend you, including questioning the legality of the traffic stop and highlighting any violations of your client’s rights during the DUI investigation. Another strategy is disputing the accuracy of the BAC tests. A DUI defense lawyer can do this by questioning the testing procedures, the personnel’s qualifications, a breathalyzer calibration flaw, a police officer’s lack of training, and the testing equipment’s maintenance. 

Breath and blood tests are critical components of DUI cases, but they are not always perfect. If you are facing DUI charges, contact a local and experienced DUI defense lawyer so you can start preparing your defense together. A knowledgeable DUI defense attorney knows how science and law mix in DUI cases and how to use both to get justice for their clients. 

Your DUI defense attorney will review your case and identify the best legal defense strategies. A drunk driving conviction on your criminal record can cost thousands in fines, fees, and higher insurance rates. An attorney can negotiate lesser charges or a diversion program. Your attorney can also defend you in court. Talk to a local and experienced DUI lawyer for legal advice in your case.