New Details Emerge About 'Affluenza' Teen's Time in Mexico

— -- New details are emerging about the time Ethan Couch -- a teen who killed four people in a car crash in 2013 -- spent in Mexico on the run with his mother while U.S. authorities searched for him.

Couch and his mother, Tonya, stayed at an apartment in Puerto Vallarta, a resort town frequented by American tourists, and visited a restaurant and butcher shop nearby, locals told ABC News. Law enforcement sources confirm to ABC News that the Couches managed to elude authorities for a time by using at least one throw away phone.

In 2013 Couch pled guilty to four counts of intoxication manslaughter and was sentenced to 10 years probation instead of jail time. In the sentencing phase his defense team had argued that he suffered from “affluenza,” meaning, they explained, that his affluent upbringing and his mother and father’s profoundly dysfunctional parenting led to his irresponsible behavior.

At the butcher shop, a worker named Luis, who did not give his last name, said Ethan Couch already had black hair when he last saw him two days ago. He said the teen paid for meat and chicken nuggets in pesos and only spoke in English – even telling the butcher he was from Texas. He said he did not recognize him as the fugitive wanted by the U.S. Marshals Service and Texas officials for allegedly skipping out on a probation check-in.

Luis witnessed Couch and his mother being escorted, handcuffed, out of the apartment by municipal police in plain clothes – right across the street from the butcher shop. He said the Couches cooperated with police and that there was no resistance.

The owner of a local eatery said Couch went into the restaurant a couple of times and sat at a table in the back. She said although there are Americans in the area, they don’t tend to eat there.

Initially, Couch and his mother stayed at a resort, Los Tules, downtown by the beach and then moved to the apartment, according to prosecutors.

Mexican prosecutors say the pair was picked up Monday at 6 p.m. local time. An order was issued for his arrest on Dec. 11 and his mother was declared a missing person, officials said. It was not clear how long they had been in Mexico.

Texas officials are convinced that Couch and his mother fled the country in a planned escape, saying in a press conference Tuesday that the mother and son drove their pickup truck across the border into Mexico.

But before Couch left town, said Tarrant County Sheriff Dee Anderson, Couch threw "something akin to a going away party “ citing an interview with an unspecified source.

Tonya Couch is expected to face charges of hindering apprehension, which could carry a sentence of between two and 10 years behind bars, Tarrant County District Attorney Sharen Wilson said.

Couch has a hearing scheduled for Jan. 19 to determine whether the case will be handled in adult court. If he is treated as a juvenile, the longest sentence he could receive is four months in confinement. He would be released when he turns 19 in April.

If his case is transferred to the adult courts he wouldn’t receive extra time if convicted. If his case is transferred to the adult courts he would likely to serve out the remainder of his original 10-year probation period and will likely have to wear tracking devices, Wilson said.

Attorneys for the Couches released a statement prior to the press conference saying they had not yet heard from them.