(CNN) -- So-called "affluenza" teen Ethan Couch and his mother have been detained by Mexican authorities near a popular Pacific resort town, officials briefed on the matter told CNN. 
       Couch, 18, went missing earlier this month in Texas where he was under probation for a 2013 drunk driving crash that killed four people and drew nationwide attention over his lawyers' use of his privileged upbringing as part of their defense at trial.
       He and his mother were detained near the Mexican beach resort of Puerto Vallarta, roughly 950 miles from home, officials told CNN on Monday. 
      The teenager is expected to be turned over to the U.S. Marshals Service, which has spent weeks searching for him. A spokesman for the service declined to comment Monday.
      Couch is wanted by authorities in Tarrant County, Texas, for allegedly violating his probation. His mother, Tonya, was listed by Texas authorities as a missing person after her son's disappearance, and the authorities said they believed she was assisting him.
Victim's husband on 'affluenza' sentence
04:09 - Source: CNN

Story highlights

Couch attorney says "whether he was involuntarily or voluntarily taken to Mexico" is under review

A hearing on moving Couch's case from juvenile to adult court is rescheduled for February 19

Fort Worth, Texas CNN  — 

Did Ethan Couch go to Mexico because someone made him?

One of his U.S.-based attorneys raised that possible scenario in a Fort Worth courtroom Tuesday and later to reporters after a hearing about Couch’s status as a juvenile was rescheduled for next month.

In court Tuesday morning, Couch’s attorney Scott Brown argued the hearing to transfer the case to adult court shouldn’t be allowed to proceed because there was no proof that Couch “voluntarily absented himself” from being at the hearing.

When asked by CNN whether Couch, the so-called “affluenza” teenager, was taken against his will to Mexico, Brown replied, “I don’t think that’s what I said. As far as Ethan being taken against his will, we are examining the facts, investigating the facts.

“This is an evolving process, and whether he was involuntarily or involuntarily taken to Mexico is something that’s being investigated.”

Before heading to Mexico with his mother, Couch was on probation in Texas for killing four people in a 2013 drunken-driving accident when he was 16. In mid-December, a warrant was issued for Couch, who’s now 18, to be taken into custody after his probation officer couldn’t reach him.

He appeared to have dropped off the radar after a video emerged that allegedly showed him at a party where alcohol was consumed.

Stephanie Patten, an attorney for his mother, Tonya Couch, acted surprised when reporters said her son’s lawyer hinted she may have taken him out of the country against his will.

“I haven’t seen any evidence that that happened,” said Patten, adding she hadn’t heard this suggestion until reporters told her about it.

Patten has said her client would plead not guilty to a charge of hindering the apprehension of a felon.

Brown also said Couch is giving up his legal battle to stay in Mexico. Brown told reporters that Couch’s Mexican attorney, Fernando Benitez, filed a document that would “release an injunction and let the (transfer) process go forward.”

CNN has reached out to Benitez for comment on whether the documents have been filed.

Benitez earlier sought to block Couch’s transfer to the United States. A Mexican judge granted the teen a temporary stay two weeks ago, halting transfer proceedings.

Couch and his mother were caught December 28 in the Pacific resort city of Puerto Vallarta after going missing a few weeks earlier. His probation officer had not been able to reach him.

Tonya Couch was almost immediately transferred to Los Angeles and later to Texas, where she has yet to enter a plea. She was released last week after posting a $75,000 bond and agreeing to abide by certain requirements such as wearing an electronic ankle monitor.

Her son resisted calls to leave Mexico. Benitez said earlier that his client could remain there for “a couple of months.” He said the teen had “committed no crime at all in Mexico” though the lawyer didn’t know whether his client had entered the country on a tourist visa.

Mother’s lawyer: No proof son forced to go to Mexico

Ethan Couch could face possible jail time for failing to live up to the terms of his probation and slipping out of the country with his mother.

His case attracted national attention and outrage in 2013 when a judge sentenced him to probation instead of jail time in the deadly drunken-driving accident.

During the trial, a psychologist testified that Couch suffered from “affluenza,” suggesting he was too rich and spoiled to understand the consequences of his actions.

‘Affluenza’: Is it real?

Hearing delayed to move case to adult court

Brown, Patten and prosecutors appeared Tuesday in a Fort Worth court for what was to be a hearing about transferring Ethan Couch’s case from juvenile to an adult court.

That hearing didn’t happen – at least in part because his parents weren’t officially notified about the legal proceeding. It was rescheduled for February 19, according to the Tarrant County criminal district attorney’s office.

The delay upset those who have been advocating for the victims in the 2013 crash.

“We are upset and disappointed it wasn’t able to proceed today,” said Jason Derscheid, executive director of the North Texas affiliate of Mothers Against Drunk Drivers. “It’s going to draw out a painful and difficult time for all the victims trying to grieve.”

Outrage, no surprise teen went on the lam

Couch’s attorneys have not spelled out why they believe he was in Mexico, where the U.S. Marshals Service tracked the teen using a cell phone linked to him, according to an official briefed on the investigation. There was speculation that he fled after video surfaced on social media showing him playing beer pong, which would have violated his probation.

The teen, who turns 19 in April, was found with a new look; his reddish blond hair and goatee had been dyed a dark color.

CNN’s Ed Lavandera reported from Fort Worth, and CNN’s Greg Botelho and Steve Almasy reported and wrote from Atlanta. CNN’s Jason Morris, Shawn Nottingham and Evan Perez contributed to this report.