Story highlights Officials say Mexican authorities have detained Ethan Couch and his mother

He's expected to be turned over to U.S. Marshals

Couch, 18, is wanted for allegedly violating his probation

(CNN) Mexican authorities have detained so-called "affluenza" teen Ethan Couch and his mother near the popular Mexican Pacific beach resort town of Puerto Vallarta, officials briefed on the matter told CNN.

Couch, 18, went missing earlier this month, two years after he made national news when he was sentenced to probation for a drunken driving crash that killed four people.

Couch is expected to be turned over to the U.S. Marshals Service, who have spent weeks searching for him. A spokesman for the service declined to comment.

He is wanted by authorities in Tarrant County, Texas, for allegedly violating probation. His mother was listed by Texas authorities as a missing person after her son's disappearance, and the authorities said they believed she was assisting her son.

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