A former Texas city councilwoman may pursue a lawsuit claiming that officials had abused their power by arresting her in retaliation for exercising her First Amendment rights, the Supreme Court ruled on Thursday.

The court’s five-page opinion was unsigned, which is unusual in argued cases. Justice Samuel A. Alito Jr. issued a 16-page concurring opinion, writing only for himself. Its length, structure and tone suggested that he had been assigned the majority opinion, but that it had failed to garner the required five votes.

Three other justices wrote or joined concurring opinions. Only Justice Clarence Thomas issued a dissent.

The unsigned opinion said an appeals court had taken “an overly cramped view” of the evidence required to prove a retaliatory arrest. The appeals court should have considered, the opinion said, objective evidence presented by the councilwoman, Sylvia Gonzalez, that the criminal law under which she had been charged had never been used in the county in similar circumstances.

The Supreme Court sent the case back to the lower court to evaluate that evidence.

Ms. Gonzalez, then 72, won a surprise victory in 2019 to become the first Hispanic councilwoman in Castle Hills, Texas. Her first official act was to help collect signatures for a petition calling for the city manager’s removal.