Ethan Couch, the infamous “affluenza”-suffering teen, remains at large – and his mother, Tonya Couch, has been added to the missing persons list.

Tonya Couch On Missing Persons List

Tonya’s mother, Ethan’s grandmother, filed a missing person’s report for her daughter over the weekend, according to the Tarrant County District Attorney’s Office. As a result, she is now officially considered a missing person.

Authorities are currently in search of Tonya’s truck, a black 2011 Ford F-150 pick-up truck with special Harley Davidson edition badging, 23-inch chrome wheels and Texas license plate BC5 0945.

“This case is very, very important to my agency and my department,” Tarrant County Sheriff Dee Anderson said. “This truck is one thing we haven’t been able to account for.”

Officials have been searching for Ethan and his mother since last week, when the teen failed to meet with his probation officer, who was also unable to make contact with Tonya. By the end of the week, Ethan was placed on Tarrant County’s most wanted list. U.S. Marshals have released a wanted poster and announced a $5,000 reward for him and/or his location.

It is believed possible that Tonya is helping her fugitive son avoid the police, and that they likely made plans in advance that will make it difficult for investigators to track them down.

“My gut feeling says they’ve gone a long way. They have the money, they have the ability to disappear,” the sheriff told Anderson Cooper on CNN’s AC 360. “I don’t believe they’re the kind of people who would have run a short distance. I believe they planned this.”

Ethan and Tonya may have gone on the run out of fear that he would face serious repercussions for allegedly violating his parole for drinking at a party. A video that surfaced earlier this month showing Ethan at a small party where beer pong was being played has been under investigation.

Ethan was sentenced to 10 years of probation, which included a ban on drinking alcohol or operating a motor vehicle, for a drunk driving accident in which he killed four people and severely injured others. The lenient sentencing sparked ire across the country, particularly as the prosecutors had argued that he suffered from “affluenza,” an affliction caused by wealthy parents who spoiled and coddled him.

If Ethan is found in violation of his parole, he could face 10 years behind bars.

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