'Affluenza' teen's mom put on Texas missing persons list: ABC News
Ethan Couch (WFAA-TV)

The mother of the teenager whose drunk driving trial included a defense witness saying that he was afflicted with "affluenza" has been listed as a missing person, making her part of the investigation into his probation violation, ABC News reported.

U.S. Marshals have issued a wanted poster for Ethan Couch, who police believe has violated the conditions of his probation. They are offering a $5,000 reward in exchange for the whereabouts of the 18-year-old, whom a psychiatrist testifying on his behalf said was so spoiled he did not know the difference between right and wrong.

A spokesperson at the Tarrant County, Texas, District Attorney's Office said that the teenager's mother, Tanya Couch, was put on the missing persons list, ABC News said late on Sunday.

"That means that she is now part of the investigation," the television network quoted the spokesperson as saying. A spokesman for the office was not immediately available to comment.

After a trial two years ago, Ethan Couch was sentenced to 10 years probation in a juvenile court for killing four people in a drunken-driving crash.

The American Psychiatric Association does not recognize affluenza as an illness, and Couch's probation sparked outrage.

Police are checking reports that Couch may have left the United States after going missing this month shortly after a video came out showing him at a beer-pong party, in a likely violation of his probation.

(Reporting by Ian Simpson; Editing by Lisa Von Ahn)