The Alabama Rules of Criminal Procedure, Rule 4.1., authorize a law enforcement officer to arrest a subject without warrant only if:
a)The law enforcement officer has probable cause to believe that a felony has been committed, …, or
b)Any offense has been committed in the law enforcement officer’s presence or view, or
c)The arrest is otherwise authorized by statute, such as Ala. Code 1975 section 32-5-171, 32-5A-191, 15-10-3.
It is a fundamental rule of criminal procedure that for a law enforcement officer to make an arrest at a third party’s residence, a valid search warrant must be employed. See, Steagald v. U.S., 451 U.S. 204 (1981). The Steagald rule has been extended to guests and invitees. Although guests and invitees will ordinarily have a somewhat lesser degree of standing to object to the search of the residence, they still possess Fourth Amendment standing. In Minnesota v. Olson, 495 U.S. 91 (1990), the Supreme Court recognized that even overnight guests have an expectation of privacy in the premises and could challenge a search directed to the guest. Thus, guests have a Constitutional right to object to a search in that part of the house in which they have a reasonable expectation of privacy. Justice Kennedy noted in Minnesota v. Olson: “…almost all social guests have a legitimate expectation of privacy … in their host’s home.” Id at 386.
Previously, in Payton v. New York, 445 U.S. 575 (1980), the Supreme Court held “that the Fourth Amendment … prohibits the police from making a warrantless and nonconsensual entry into a suspect’s home in order to make a routine felony arrest.” The fact that the arrest was beased on a misdemeanor offense (violation of a child support order) makes the warrantless arrest of the girlfreind even more egregious.
In my estimation, there is a probable violation of the 4th Amendment if the facts you have alleged are correct.