In most states, an arrest can be made on any of these grounds. However, in jurisdictions where the common law rule has not been statutorily modified, a warrantless arrest can usually be made only on the grounds of (1) and (2) above. In some states, it should be noted, DUI offenses are treated as felonies for purposes of arrest, which means that an arrest can be made under any of the three grounds listed above.
It is clear in every jurisdiction that a police officer can make a warrantless arrest for a DUI-DWI offense committed in the presence of the officer. For this rule to apply, however, every element of the offense must be committed in the presence of the officer. Specifically, the officer must observe both the operation of the vehicle by the defendant and evidence of intoxication. An arrest made by an officer who did not personally see the defendant operate the vehicle has been held unlawful under this rule. The requirement of presence is most often imposed in arrests made by city or local law enforcement officers who, in some states, are not covered by state statutes modifying the presence requirement.
Even in situations where the presence requirement is imposed, an arrest without a warrant is usually permitted when exigent circumstances exist. In DUI cases, exigent circumstances include hot or continuous pursuit, protection of public safety, the need to prevent the defendant from fleeing, and the need to prevent the destruction of evidence.
In most jurisdictions, a police officer may also make an arrest (other than an in-home arrest) for a drunk or impaired driving offense without a warrant if the officer has “probable cause” to believe that the person arrested has committed such an offense. “Probable cause” may consist of either the officer’s own observations and firsthand knowledge or trustworthy information provided to the officer by others, including other police officers. If the officer’s information is supplied by a citizen, the citizen must be an eyewitness to the offense or have firsthand knowledge of the incident.