The Texas teenager who used an "affluenza" defense in a deadly drunken-driving wreck arrived in Dallas on a commercial jet from Mexico City Thursday, one month after he and his mother allegedly fled the United States.

Ethan Couch, 18, wearing a bluish camouflage-print hoodie, arrived at Dallas-Fort Worth International Airport on the Aeroméxico plane before law enforcement escorted him to a juvenile detention center.

A judge will hold a hearing Friday in Fort Worth to decide whether to continue to hold him in at that facility, book him in an adult jail or let him go, Tarrant County Sheriff's Deputy Ed Wiseman said. Couch and his mother, Tonya, allegedly fled Texas while prosecutors investigated whether he had violated his probation.

The attorneys for Couch said they are optimistic their client will not run afoul of the law during the rest of his probation.

Scott Brown and Reagan Wynn issued a statement Thursday  afternoonin which they also predicted Couch would remain in a juvenile facility until a judge decides Feb. 19 whether to transfer his case to the adult system.

If it is transferred and Couch violates his probation again, he could face up to 40 years in prison.

The teen formally ratified his decision to drop an appeal against deportation on Monday. He had been in immigration custody for 28 days.

Couch, seen with a full, light-brown beard, showed little emotion as he was placed aboard a pickup truck and driven out of the gated detention center Thursday morning.

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The teen and his mother were detained in the resort of Puerto Vallarta in December after a call for delivery pizza tipped off authorities to their whereabouts. His mother was quickly sent back to the U.S. She was released after posting bail.

"It’s more than overdue for Couch to be held accountable... We must ensure Couch gets prison, and not a present for his 19th birthday in April," Mothers Against Drunk Driving National President Colleen Sheehey-Church said.

According to an arrest warrant, Tonya Couch is accused of telling her estranged husband, Fred Couch, that he would never see her or his son again before fleeing.

The teen was driving drunk and speeding near Fort Worth in June 2013 when he crashed into a disabled SUV, killing four people and injuring several others, including passengers in his pickup truck. He was 16 at the time. He pleaded guilty in juvenile court to four counts of intoxication manslaughter and two counts of intoxication assault causing serious bodily injury. He was sentenced to 10 years' probation.

During the sentencing phase of his trial, a defense expert argued that he had been coddled into a sense of irresponsibility. "Affluenza" is not recognized as a medical diagnosis by the American Psychiatric Association, and its invocation drew ridicule.

The Associated Press contributed to this report.