Mother of 'Affluenza' Teen Wanted for Alleged Probation Violation Put on Missing Person's List

— -- 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 the teen's probation violation, authorities said.

The U.S. Marshals issued a wanted poster Friday for Ethan Couch, who police believe has violated the conditions of his probation, and are offering a $5,000 reward in exchange for the 18-year-old's whereabouts.

A spokesperson at the Tarrant County, Texas, District Attorney's Office said today that the teen's mother, Tanya Couch, was put on the missing person's list."

"That means that she is now part of the investigation," the spokesperson said.

Couch was convicted of four counts of intoxication manslaughter in 2013 but was not sentenced to any jail time; instead he was given 10 years probation -- a punishment considered a mere slap on the wrist by critics, and one that outraged the victims' families.

It was not clear how long he's allegedly been at large.