PHOENIX — Former Sheriff Joe Arpaio was convicted of a criminal charge Monday for refusing to stop traffic patrols that targeted immigrants, marking a final rebuke for a politician who once drew strong popularity from such crackdowns but was ultimately booted from office as voters became frustrated over his headline-grabbing tactics and deepening legal troubles.

The federal judge’s verdict represents a victory for critics who voiced anger over Arpaio’s unusual efforts to get tough on crime, including jailing inmates in tents during triple-digit heat, forcing them to wear pink underwear and making hundreds of arrests in crackdowns that divided immigrant families. Arpaio is vowing to appeal.

Arpaio, who spent 24 years as the sheriff of metro Phoenix, skirted two earlier criminal investigations of his office. But he wasn’t able to avoid legal problems when he prolonged his signature immigration patrols for nearly a year and a half after a different judge ordered him to stop. That judge later ruled they racially profiled Latinos.

The lawman who made defiance a hallmark of his tenure was found guilty of misdemeanor contempt-of-court for ignoring the 2011 court order to stop the patrols. The 85-year-old faces up to six months in jail, though attorneys who have followed the case doubt someone his age would be incarcerated. He will be sentenced Oct. 5.

Critics hoped Arpaio’s eight-day trial in federal court in Phoenix would bring a long-awaited comeuppance for lawman who had managed to escape accountability through much of his six terms.