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FORT WORTH (CBSDFW.COM) – The FBI and U.S. Marshals are now getting involved in the search for Ethan Couch.

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Tarrant County Sheriffs say Ethan Couch is the top fugitive they are trying to find, and believe that he and his mother have not only skipped town, but possibly the country.

Couch was serving ten years probation for killing four people while driving drunk. His lawyer argued Couch didn’t understand consequences because of his parent’s wealth.

Couch missed a meeting with his probation officer, and when officers went to his home, they found it empty.

Nicole Knox is a Dallas defense attorney and says Couch’s mother could face charges if the two are caught.

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“If law enforcement can present to the DA’s office, facts that the mother in fact aiding in Ethan Couch violating probation, then there might be a basis for her obstructing justice.”

As for Couch, Knox says he could face severe penalties.

“It would be up to a judge whether or not his probation has been violated. The judge could find that he violated his probation and terminate his probation and sentence him up to ten years in prison.”

Authorities are also looking for anyone who may have helped Couch leave the area.

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