St. Louis Area Police Use Outdated Tech to Enforce DWIs

If you are stopped for suspicion of DWI in the greater St. Louis area, it is likely that the police officer will request that you submit to a breath test. Breath tests are intended to provide an estimate of your Blood Alcohol Concentration (BAC). What if the police use an outdated and inaccurate device to estimate your BAC? This happens to thousands of drivers in the St. Louis area. Many of these drivers are charged with DWI and spend thousands of dollars defending themselves. Shouldn’t police officers in Missouri use the most accurate testing devices on the market? You would think so.
Instead, police officers in the St. Louis area have been increasingly relying on a device called the Alco-Sensor IV (ASIV) for breath testing. The ASIV operates on old technology and was first put into service in the mid-1990s. It has no filters to detect mouth alcohol. It has no slope detector. The safeguards that more advanced breath testing devices have employed do not exist with the ASIV.
Police officers often perform a Preliminary Breath Test (PBT) as part of roadside sobriety testing. The State of Missouri does not consider PBT devices accurate enough to be used in court. They use the same technology as the ASIV. The ASIV is, in simple form, a PBT with a printer attached. One manufacturer was given permission to build and sell the ASIV as an evidentiary device in Missouri. Strange loophole.
ASIV devices are about 1/3 the price of more accurate breath testing devices. They are portable, and can be used on the roadside. The lower cost and easy portability of the ASIV has made it a favorite for law enforcement agencies. Approximately 185 ASIV devices are in use throughout Missouri.
The Missouri legislature recently defunded sobriety checkpoints throughout the state. In their place, the Missouri State Highway Patrol has been running “saturation patrols” seeking to write has many DWIs as possible in a defined area over a targeted weekend. The troopers who run these patrols casually call themselves the “wolf pack”. What is the device they have been turning to during these saturation patrols? Generally the ASIV. The ASIV has more potential to give an inaccurate BAC result than any other evidentiary device used in Missouri. If you are stopped by a police officer for suspicion of DWI, ask to speak with a lawyer before deciding whether or not to take a breath test.

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