Law enforcement has new technology available that may drastically impact driving under the influence (DUI) cases in San Diego and throughout California. A new wave of rapid roadside drug-screening devices—including the SoToxa drug testing device—is being adopted by police departments throughout the state, including San Diego County, to detect recent drug use by drivers. This includes cannabis, opioids, methamphetamine, cocaine, benzodiazepines, and other substances.
While these devices may promise fast results, they raise important legal concerns for anyone suspected of driving under the influence of drugs. This article helps explain this new rapid drug testing technology, how law enforcement is starting to use it, and possible defense strategies if you are charged with driving under the influence of drugs in San Diego.
How do SoToxa Devices Work?
This technology, created by Abbott Diagnostics, was designed to test for recent drug use by measuring the active presence of drug compounds in one’s system. An officer using this device during a DUI stop will ask the driver to swab the inside of their mouth, then insert the swab into the device and wait a few minutes for the result. The device measures six different drug types and alerts positive if there is a certain amount of nanograms present. The device only measures if drug compounds are present—it does not measure one’s level of impairment. Abbott Diagnostics claims their device has an accuracy rate of more than 90% and should be followed up with a secondary standard blood test to confirm a positive result.
How does this technology impact DUI drug enforcement in California?
This new technology will likely increase roadside drug screening by law enforcement. It allows for faster and more portable testing, like that of a breathalyzer used in standard DUI stops to test for alcohol consumption. A positive SoToxa test may give officers probable cause to conduct further DUI-related testing and/or arrest someone for driving under the influence of drugs. As this technology becomes more available and accurate, prosecutors may soon rely on these devices to build cases, in addition to standardized field sobriety tests and other factors in DUI cases. This may also result in accelerated charging decisions and increased prosecutions that are often delayed due to pending chemical test results or lack of other probable cause.
What Matters Legally in California DUI-Drug Cases?
The government must prove in any DUI prosecution that: (1) the defendant was driving; and (2) that their driving was impaired by the consumption of alcohol and/or drugs. The presence of alcohol or drugs alone in one’s vehicle is not proof of impairment. There is a legal presumption in California that anyone with a blood alcohol concentration (BAC) or 0.8% of greater is impaired for purposes of a DUI prosecution. That is why most of these cases settle before trial where the defendant had a 0.8% or higher BAC. If that is the case, it is easier for the government to meet their burden and prove all of the required elements to secure a DUI conviction.
There is no presumption a person is “legally impaired”, however, in DUI-drug cases. This makes it more difficult for the government to prove that a driver was impaired by drugs, even if they can corroborate that the driver had drugs in their system through other evidence such as the SoToxa device. Chemical testing, including blood or urine tests, are often used to demonstrate that a driver had a high concentration of drug compounds at the time they were driving. A prosecutor will argue they were impaired for purposes of a DUI conviction with this evidence, even if the person was able to safely operate a motor vehicle.
Defense Challenges to Rapid Drug Testing Technology like SoToxa.
This type of rapid drug testing technology raises significant legal concerns in the context of defending DUI-drug cases. There are several different challenges that can be made to counter the reliability of this evidence if used by the government during a DUI-drug prosecution. This includes:
- Distinguish presumptive vs. confirmatory evidence:
Devices like SoToxa are meant to be initial screening devices only. They still require further chemical testing to confirm the presence of drugs in your system and level of impairment. If you test positive on one of these devices but believe the results are inaccurate, your defense attorney may advise you to promptly seek independent lab testing and try to obtain negative test results to show that you were not under the influence at the time you were driving.
- Accuracy and expert use:
Technology like the SoToxa device is new and not always accurate. Your defense attorney may want to question the validity of such rapid drug testing results if the government attempts to use them against you in a DUI-drug prosecution. Your attorney can also question who is qualified to use the device, how they are trained, how the device is maintained/stored, what the chain-of-custody is for the results, and whether the operating officer followed protocol when using and storing the device. Improper use, missing or inconsistent records, and lack of training or continued education may produce false positive/negatives and impact the reliability of results in a DUI-drug case.
- Motions and evidentiary strategies:
Your defense attorney may file motions to exclude or limit evidence of rapid drug testing device results if the government attempts to use this new technology in a DUI-drug prosecution. Where appropriate, admissibility challenges can also be made to question such novel-testing methods, lack of impairment correlation, or other constitutional issues (e.g., lack of probable cause for the initial stop or improper sample collection).
Proactive Defenses to Rapid DUI-Drug Testing Technology
Rapid drug screening devices, like SoToxa, enable faster drug use detection and increased screening capabilities during DUI stops. This technology is being used on a regular basis by law enforcement across the country. As of December 2025, nearly 100% of law enforcement agencies in California have SoToxa devices, including the San Diego Police Department. While this may result in increased DUI-related arrests and prosecutions, it is important to remember that there are often contestable grounds against the validity of such devices. Defense attorneys should be proactive and challenge the admissibility of devices like SoToxa if used during a DUI-drug prosecution.
Experienced DUI-Drug Criminal Defense Attorney
At the Law Offices of David Silldorf, we always stay up to date with this new wave of drug testing technology and how it may impact our DUI clients. It is critical for defendants arrested for driving under the influence of alcohol or drugs to understand their rights, what legal challenges can be raised, and how this technology is being increasingly implemented by law enforcement. If you or a loved one is facing DUI drug or alcohol charges in San Diego, contact the Law Offices of David Silldorf to learn how we can help fight your case.
