Ala. Code § 32-5-171: Arrest Without Warrant; Issuance of Traffic Citation.

(a) A law enforcement officer as defined in Section 36-21-40, may arrest, at the scene of a traffic accident, any driver of a vehicle involved in the accident if upon personal investigation, including information from eyewitnesses, the officer has reasonable grounds to believe that the person by violating Section 32-5A-191 contributed to the accident. He or she may arrest such a person without a warrant although he or she did not personally see the violation.

(b) A law enforcement officer, as defined in Section 36-21-40, subsequent to a traffic accident, may issue a traffic citation to a driver of a vehicle involved in the accident when, based on personal investigation, the officer has prima facie evidence demonstrating grounds to believe that the person has committed any offense under Chapter 5, 5A, 6, 7, or 7A of Title 32.