The Fourth Amendment to the United States Constitution prohibits unreasonable searches and seizures and arrests without a warrant. Because a DUI arrest is one without a warrant, it is presumed unconstitutional. That means that if your lawyer raises the issue, the prosecution must prove the officer had a reasonable suspicion of crime to stop you in the first place and probable cause to arrest you afterward. Fourth Amendment defenses include:
DUI Defense #1
→ No facts to justify the original stop.
DUI Defense #2
→ No facts to justify detaining you for DUI.
DUI Defense #3
→ No facts to justify the arrest for DUI.
DUI Defense #4
→ No grounds to justify search of you or your car.