The Definitive Guide to Mississippi DUIs - Part 4
What is the Preliminary Breath Test?
The Preliminary Breath Test, or "PBT," is a handheld device that is used by officers on the roadside to help them determine whether alcohol is present on a person's breath. You may hear it called a "handheld" or a "portable breath test." These devices are made by multiple different manufacturers, and differ in their appearance. (There are over 20 different PBT models approved for use.) They are usually approximately the length of a smartphone but a bit thicker, and have a replaceable straw sticking out of the side. There is a screen on the front that gives the officer an approximate reading of your BAC.
According to the Department of Justice, a PBT is "an objective roadside blood alcohol content (BAC) chemical test." Because it is a test of one's breath, it is a search under both the Mississippi and United States Constitutions. The PBT is not calibrated, and although it produces a number signifying a person's breath alcohol content that number is not admissible in court. A driver can refuse to take a PBT without legal penalty. Essentially, a PBT is the "light" version of the Intoxilyzer 8000, which is the standard machine used to analyze a driver's breath sample in Mississippi DUI enforcement. It is the Intoxilyzer 8000 result that is used in court. (More about the Intoxilyzer 8000 in a future post.)
What role does the Preliminary Breath Test play in a DUI investigation?
As we've referenced before, the National Highway Traffic Safety Administration (NHTSA) created the training program used to certify officers to conduct DUI investigations in America. There are multiple steps to a DUI investigation that occur before an officer makes a decision to arrest a driver for DUI. (You can read about those here and here.) Those steps exist to guide the officer in determining whether he has probable cause to arrest the driver, and that's extremely important because it is unconstitutional to arrest someone without probable cause.
The NHTSA teaches officers that the PBT is to be used as a final step in deciding whether to make a DUI arrest. Essentially, it is there to confirm what the officer has already gathered through the other steps in the investigation, including the Standardized Field Sobriety Tests (SFSTs). The NHTSA training materials explicitly tell officers that PBT results should not be the sole basis for a DUI arrest, and - importantly - that a PBT should be administered after the SFSTs. This is where the wheels have come off in Mississippi.
Where Mississippi officers are often making mistakes
A few years back, we started seeing officers rely far too heavily on PBTs in DUI investigations. As mentioned above, they are trained not to administer a PBT until after the SFSTs and to not use the PBT as the sole basis for a DUI arrest. Unfortunately, we've seen both things occur. In more than one instance, we've seen officers initiate a traffic stop, ask the driver to get out of the car, and ask them to blow in the PBT. Even worse, we've had officers walk up to the driver's side window with the PBT prepared, and simply put it in the driver's face and tell them, "blow in this." I'm not sure if they'd been trained that way at the Mississippi Law Enforcement Officer Training Academy, but I doubt it. Regardless, it has become standard operating procedure at some police departments to skip right to the PBT, which is in clear violation of NHTSA training.
Are PBTs mandatory?
No. Unlike the Intoxilyzer 8000, a driver is under no obligation whatsoever to take a PBT. Unless a driver has had absolutely nothing to drink, the only thing they are doing when taking a PBT is giving the officer another piece of evidence to use against them in forming probable cause for their arrest.
In Part 5 of the Definitive Guide to DUIs in Mississippi, we'll cover the Intoxilyzer 8000 and the question every lawyer has heard a hundred times: "should I blow?"