Ethan Couch, imprisoned for a 2013 accident that killed four people when he was a teenager, was released from custody in the afternoon, Tarrant County Sheriff's spokesman David McClelland told AFP.
"He went over to supervision, which is our probation," McClelland said. Couch's lawyers told ABC News that he would serve six years' probation.
The then-16-year-old son of millionaire parents crashed his pickup truck into a group of pedestrians and another vehicle.
He made headlines when a psychologist testifying on his behalf claimed that the teen suffered from "affluenza."
The term, coined from affluence and influenza, implied that financial privilege made the teenager unable to understand the consequences of his actions.
At the time of the crash in Texas, Couch had a blood-alcohol level nearly three times the legal limit for an adult. He pleaded guilty to four counts of intoxication manslaughter.
Ethan Couch, after he was taken into custody in Puerto Vallarta, Mexico. Source: Jalisco state prosecutor office
Prosecutors had sought a 20-year prison term, but a juvenile court handed Couch a sentence of mental health treatment and a decade of probation.
The sentence caused outrage among many Americans, who considered it too lenient.
After Couch missed a mandatory meeting with his probation officer in 2015, he and his mother fled to Mexico. They were arrested in the resort of Puerto Vallarta after a manhunt.
"Two years in jail for four people killed is a grave injustice to the victims and their families who have been dealt life sentences," the group Mothers Against Drunk Driving said in a statement ahead of Couch's release.
Couch was also to be monitored for alcohol and drug use, and would be unable to drive a vehicle without a monitoring device that checks for alcohol consumption, according to The Dallas Morning News newspaper.
"From the beginning, Ethan has admitted his conduct, accepted responsibility for his actions, and felt true remorse for the terrible consequences of those actions," Couch's lawyers Scott Brown and Reagan Wynn said in a statement to ABC News.
