Category: Before the Stop

When an officer is on patrol, he may have as part of his assignment to be on the lookout for drunk or otherwise impaired drivers. Normally, officers who are given this task have been specially trained in DUI enforcement through the Mississippi Law Enforcement Officers Training Academy (MLEOTA) in Pearl. If they were not trained at MLEOTA, they typically received DUI enforcement training somewhere. And almost always, the training any officer receives is based upon standardized DUI educational materials authored by the National Highway Traffic Safety Administration (NHTSA), which is part of the United States Department of Transportation.

The standard DUI training from NHTSA covers everything from an officer’s first view of a car in motion through arrest and reporting. The first part NHTSA covers is “vehicle in motion” observation. 

Vehicle in Motion

When an officer sees a car moving down the roadway, he is taught to look for clues that its driver might be impaired. There are four categories of clues that officers are taught to look for to detect potential driver impairment, along with examples the officers are given:

• Problems in maintaining proper lane position
  • Weaving
  • Crossing lane lines
  • Drifting
  • Straddling a lane line
  • Swerving
  • Nearly running into another vehicle or object
  • Turning with a wide radius
• Speed and braking problems
  • Stopping too short or too far
  • Braking in a “jerking” fashion
  • Unnecessary speeding up or slowing down
  • Varying speed
  • Driving 10mph or more under the speed limit
• Vigilance problems
  • Not turning headlights on at night
  • Failing to use turn signal or using it incorrectly
  • Driving in the wrong lane (against traffic)
  • Stopping for no apparent reason
• Judgment problems
  • Following too closely
  • Improper lane change
  • Illegal turn
  • Driving off of the road

Officers are taught that some of these clues are more indicative of DUI than others, but that the presence of any single one of them means there is a 35% chance the driver is impaired. For example, NHTSA says that weaving across lane lines means there is a 50% chance the driver is impaired, while swerving (an abrupt jerking of the car into another direction of travel to correct drifting) means there is a 70% likelihood of impairment. When any two clues are combined, the officers are taught that there is at worst a 50% chance that the driver is impaired.

Officers only need probable cause (generally defined as more likely than not, or more than 50% likely) to  believe a driver is impaired to initiate a traffic stop. So if they see a vehicle swerve, or if they see a driver follow too closely and then change lanes without using a signal, they will feel confident that they can stop the driver under suspicion of DUI.

If the officer decides to stop the car, he or she then watches the way in which the driver stops the car for more clues of impairment. They are taught to watch for the following:

• Trying to flee
• No response to the blue lights or a slow response
• Abruptly weaving
• Sudden stop
• Hitting the curb while stopping
• Any new traffic violation

This first phase, Vehicle in Motion, is an important evidence gathering phase for the officer, who is building his DUI case from that very moment. If you wind up charged with DUI, you can expect to see some of the above referenced in the officer’s report. The next phase is when the officer first interacts with the driver, which you can learn more about in Step 2 – First Contact with Law Enforcement.

Drivers have basic legal obligations concerning sobriety on Mississippi roadways. Section 63-11-30 of the Mississippi Code is the statute that governs operating a motor vehicle while under the influence of alcohol or other substance. The first subsection of 63-11-30 lays out exactly what a person can’t do, and we’ll spend time on that in this post.

The first subsection of 63-11-30 reads:

(1) It is unlawful for a person to drive or otherwise operate a vehicle within this state if the person:

(a) Is under the influence of intoxicating liquor;

(b) Is under the influence of any other substance that has impaired the person’s ability to operate a motor vehicle;

(c) Is under the influence of any drug or controlled substance, the possession of which is unlawful under the Mississippi Controlled Substances Law; or

(d) Has an alcohol concentration in the person’s blood, based upon grams of alcohol per one hundred (100) milliliters of blood, or grams of alcohol per two hundred ten (210) liters of breath, as shown by a chemical analysis of the person’s breath, blood or urine administered as authorized by this chapter, of:

(i) Eight one-hundredths percent (.08%) or more for a person who is above the legal age to purchase alcoholic beverages under state law;

(ii) Two one-hundredths percent (.02%) or more for a person who is below the legal age to purchase alcoholic beverages under state law; or

(iii) Four one-hundredths percent (.04%) or more for a person operating a commercial motor vehicle.

So basically you can’t be drunk or high while driving, or you are in violation of this statute. (1)(a) and (1)(d) deal with alcohol, while (1)(b) and (1)(c) cover being impaired by a substance other than alcohol. Of course someone may be in violation of a statute, but later be found not guilty in court or have their charges dismissed. How that happens is a whole other ball of wax.

More and more, we are starting to see DUI charges issued under (1)(b) and (1)(c). If a person is accused of driving while high on marijuana, he will be charged under (1)(b) and/or (1)(c). Same for cocaine, codeine cough syrup, etc. But still the most frequent types of DUI charges in Mississippi are alcohol-related, and fall under (1)(a) and (1)(d). DUI charges under (1)(a) are usually called “common law DUIs” to distinguish them from (1)(d) charges, which are supported by a blood alcohol content reading from a machine that analyzes a DUI suspect’s breath for alcohol content.

What is the purpose of common law DUI? Common law DUIs existed back before the technology was developed to somewhat accurately measure the amount of alcohol in a person’s bloodstream. They are still around because people can refuse to give a breath sample or may be physically unable to provide one, and because sometimes the testing machines are not available. In those instances, there is no machine reading for purposes of subsection (1)(d).

You’ll notice that the subparts of (1)(d) have different BAC levels for different types of drivers: regular adult drivers, drivers who are minors, and people who are driving commercial vehicles (think 18 wheelers and busses). That’s because minors aren’t supposed to be drinking at all, and because commercial vehicle drivers are behind the wheel of large vehicles that can do a lot of damage very quickly.

So that is the 10,000-foot view of the main portion of Mississippi’s most important DUI statute. In the next part, we’ll go into what DUI enforcement officers are taught about identifying potentially impaired drivers both before stopping the car and before asking the driver to exit the vehicle.

And remember, if you need help right away, contact the Eichelberger Law Firm as soon as possible.