You may not realize it, but distinct differences exist between reasonable suspicion and probable cause. Even so, both are necessary in order to make an arrest for driving under the influence.
So, what is the difference between the two? Reasonable suspicion is all that police need in order to initiate a traffic stop, but the officer needs probable cause in order to make an arrest.
What constitutes reasonable suspicion?
Reasonable suspicion rests in an officer's belief that you may be involved in criminal activity such as drunk driving. The officer may initiate a traffic stop, detain you briefly and conduct a limited investigation designed to either confirm or deny that belief. Examples of reasonable suspicion for a DUI stop include the following:
- Making an illegal turn
- Straddling the center line
- Frequently braking
- Drifting in and out of your lane
- Driving slowly or erratically
These are just some of the observations made by an officer that constitute reasonable suspicion. Nearly any behavior the officer believes indicates impairment could provide the officer with enough evidence to meet this requirement.
Now for the probable cause
Once stopped, an officer cannot simply arrest you for DUI based on reasonable suspicion. For that, probable cause is a requirement. Field sobriety tests and breath tests, among other things, help officers establish the required probable cause for an arrest. The threshold is higher since, upon arrest, the officer denies you of your ability to leave and detains you for longer than allowed otherwise.
Where reasonable suspicion only requires the possibility that you might have committed a crime, probable cause requires meeting the requirement that it's likely you committed a crime. To summarize, only reasonable suspicion is a requirement for a DUI stop, but probable cause is necessary for a DUI arrest.
Your challenge of the charges begins with the traffic stop
Even though nearly any activity on your part could provide an officer with reasonable suspicion, it does not mean that your defense ignores the initial traffic stop. On the contrary, what led to the initial stop may be crucial to your case. After all, had the officer not stopped you, the arrest may not have followed.
After reviewing the circumstances surrounding the DUI stop, your defense then turns to the events that led to the DUI arrest. Did the officer correctly administer the field sobriety tests? What about the breath test? Did the officer have the proper training and certification to perform either or both? These questions need answering before going any further.