Like every other state, Mississippi has a legal limit at which authorities would consider you impaired. When it comes to alcohol, the legal limit generally means a blood alcohol content of .08 percent or higher. However, an officer could place you under arrest on suspicion of DUI with a BAC lower than .08 depending on the circumstances.
You could also face charges for DUI for using drugs that impair your ability to drive, which includes prescription medications. The question that you and many other people ask is: what turns a traffic stop into an arrest for driving under the influence?
The officer's observations
All traffic stops begin with a police officer observing some sort of behavior that indicates a driver is violating a traffic law or behaving erratically. For example, if an officer observes you speeding, running a stop sign or weaving in and out of your lane, he or she could initiate a traffic stop. The observed behavior often serves as the first component of building probable cause for a DUI arrest.
Once pulled over, the officer will approach you and attempt to ascertain why you were driving in a certain manner. The officer will observe you to determine whether your eyes are bloodshot, your speech is slurred or you smell of alcohol. If the officer finds no signs of impairment, he or she may give you a citation and allow you to go about your day. If any additional signs of possible impairment exist, the officer will more than likely ask you to exit your vehicle.
The officer's requests for roadside sobriety tests
The officer may ask you to participate in field sobriety tests. You should know that you are not legally obligated to participate in these tests. The officer may attempt to convince you otherwise, however. If you decide not to participate, calmly and politely decline. Many people fail these tests even when sober since many other factors can influence their results, not the least of which is the subjectivity of the officer.
Not participating in roadside sobriety tests, including a preliminary breath test, may not prevent an arrest, but can keep you from helping the officer establish probable cause. Field sobriety tests and the roadside breath test do not violate the consent you gave when you acquired your driver's license. However, refusing the chemical test at the police station or jail would. The blood or breath test usually happens after your arrest, so it does not necessarily provide the officer with probable cause since you are already in custody at that point.
You may challenge any aspect of your contact with the officer or officers who arrested you. If you believe the officer did not have reasonable suspicion to stop you, that may be a place to start. If you did participate in field sobriety tests or submit to a roadside breath test, those results may also provide you with a place to challenge your arrest since a lack of probable cause could invalidate it.