Affluenza teen Ethan Couch, mother detained in Mexico

Infamous affluenza teenager Ethan Couch and his mother have been found in Mexico and are headed back to the United States, but the teen's punishment could be surprisingly short.

Tarrant County Sheriff Dee Anderson said he's been told they were pulled over by Mexican authorities and detained near the popular beach resort Puerto Vallarta Monday afternoon.

Ethan and Tonya could be back in the U.S. as soon as Wednesday, as U.S. Marshals are still working with the Mexican authorities to get them back to Tarrant County. Once they are back in the country, Tonya will be charged for hindering an arrest, with a conviction resulting in two to 10 years in prison.

But Ethan Couch could wind up only spending four months in jail for fleeing the country. Ethan will be returned to juvenile detention when he returns and that's when a series of rulings and decisions will determine what happens.

Tarrant County District Attorney Sharen Wilson said her office has already requested a hearing scheduled for Jan. 19 to transfer the case to the adult system.

If the judge opts to keep the case in juvenile court, then Couch could go free after serving time in detention until he turns 19 in April.

If the judge agrees to send the case to the adult system, a judge could sentence him to up to 120 days in jail and Ethan would be under supervision for his probation term. Couch would then be held to adult standards and if he violations his probation again he could get 10 years in jail for each fatality case.

"Four months of confinement. That, in my opinion, is not sufficient punishment for the taking of four lives," Wilson said.

Anderson said a fugitive task force had been working tirelessly to find the pair. He said the media publicity helped and they received numerous tips from both close friends and members of the general public who reported seeing them.

Ethan, who killed four people while driving drunk in 2013, and his mother, Tonya, went missing about two weeks ago. Ethan missed an appointment with his probation officer, leading authorities to believe he was on the run from law enforcement and had possibly fled the country.

Earlier this month the Tarrant County DA'S office began investigating a video posted online that appeared to show Ethan at a party where alcohol was involved - a violation of his probation. The clip showed several young men playing beer pong. It's believed the release of the video caused Ethan to flee.

Investigators now believe the teen and his mother always had a plan to disappear, although there is no indication that his father was involved.

"They basically had a gathering before they left and kind of characterized it as a going away party, which to us meant that what we suspected had happened. It was carefully planned and timed to get out of the country," Anderson said.

In the days before Christmas, authorities asked people to search for Tonya's vehicle, a black 2011 Ford F-150 pick-up truck. Anderson said the task force received tips indicating that they did indeed cross the border in that truck.

The sheriff said the Couches were wise to go to Puerto Vallarta where there are a lot of American tourists during the Christmas holiday. He credited "good police work" for finding out where they were staying.

A photo of Ethan in Mexican custody shows he now has darker hair. Anderson said it's pretty obvious he tried to change his appearance, but is still recognizable.

Anderson also said he's not surprised that Tonya helped her son disappear. She was determined that he not be held accountable during his trial, he said.

In 2013, Ethan was convicted of intoxication manslaughter and sentenced to 10 years of probation for driving his pickup truck drunk and killing four people.

Prosecutors said his alcohol level was three times the legal limit when he caused the chain reaction crash in Burleson. The crash killed a 24-year-old stranded motorist, a youth pastor who stopped to help her and a mother and daughter who lived nearby. They were all working to change a flat on the side of the road.

Ethan was found guilty, but the defense argued he had "affluenza." Attorneys said he was the product of a dysfunctional and abusive family -- parents who condoned drug and alcohol use and never set boundaries. He was given probation and sent to a pricey rehab facility in California.

In reference to the victim's families, Anderson said he hopes justice will be served this time around. His department responded to the fatal crash and he said he doesn't believe Ethan received an appropriate punishment.

"I just want to tell them that we have done everything humanly possible to bring justice. As I've said many times I don't think initially justice was served," he said.