Tonya Couch, mom of 'affluenza' teen Ethan Couch, listed as missing person

Tonya Couch, 48, has been listed as a missing person. Authorities are also looking for her 18-year-old son, Ethan Couch, who is believed to have fled after missing an appointment earlier this month with his probation officer, Dec. 21, 2015. less Tonya Couch, 48, has been listed as a missing person. Authorities are also looking for her 18-year-old son, Ethan Couch, who is believed to have fled after missing an appointment earlier this month with his ... more Photo: Courtesy Of Tarrant County Sheriff's Office Photo: Courtesy Of Tarrant County Sheriff's Office Image 1 of / 24 Caption Close Tonya Couch, mom of 'affluenza' teen Ethan Couch, listed as missing person 1 / 24 Back to Gallery

As the latest development in the hunt for an affluent Dallas-area teenager suspected of violating his probation terms, authorities are looking for his mother and her truck.

The Tarrant County Sheriff's Office on Monday posted photos of Tonya Couch, 48, and the rear of her 2011 black Ford F-150 with Texas license plate BC5-0945.

Her son, 18-year-old Ethan Couch of Burleson, is believed to have fled with his mother after he missed an appointment with his probation officer earlier this month.

According to the sheriff's office Facebook post, the truck has "special Harley-Davidson Edition badging" and 23-inch chrome wheels, with "crease-like damage" to the passenger side rear panel.

A spokesman for the Tarrant County District Attorney's office told the Associated Press on Monday that a relative of Tonya Couch had filed a missing person report for her over the weekend.

Ethan Couch, who was sentenced to 10 years probation in 2013 for killing four people in a drunken-driving accident on June 15, 2013, had reportedly been living with his mother. His parents are divorced, and his father told authorities last week that he hadn't heard from his son or ex-wife in about two weeks.

During the sentencing phase of his juvenile court trial in 2013, a defense expert argued that Couch was irresponsible because his wealthy parents had coddled him, a condition the expert termed "affluenza," drawing widespread ridicule and outrage.

The U.S. Marshals Service is offering a reward of up to $5,000 for information on Ethan Couch's whereabouts.

Anyone with information on Couch is asked to contact the U.S. Marshals at 800-336-0102 or the Tarrant County Sheriff's Office at 817-884-1213.