FORT WORTH, Texas -- Lawyers for a Texas teen who used an “affluenza” defense after a deadly 2013 DUI wreck are arguing he should be released from jail because a judge in the case didn’t have jurisdiction to rule, reports CBS DFW.

Ethan Couch was 16 years old when he crashed his car into a disabled SUV outside Fort Worth while his blood alcohol level was nearly three times the legal limit. Four people were killed and others were injured. Couch, now 19, pleaded guilty to four counts of intoxication manslaughter and two counts of intoxication assault causing serious bodily injury, but was sentenced to rehabilitation and 10 years probation, causing public uproar.

During the sentencing phase of his trial, Couch’s attorneys relied on a defense expert who argued that Couch’s wealthy parents coddled him into a sense of irresponsibility — a condition the expert termed “affluenza.” The condition is not recognized as a medical diagnosis by the American Psychiatric Association, and its invocation drew widespread ridicule.

Authorities say Couch and his mother, Tonya, fled the U.S. to Mexico in December, as Texas prosecutors investigated whether a video showing the teen at a party where alcohol was present meant he violated his probation. He was extradited and ordered in April to serve nearly two years in county jail.

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But according to a new motion filed by Couch’s attorneys, juvenile cases like Couch’s are considered to be civil proceedings. A judge who presided over the case, however, was a Tarrant County criminal court judge, they argue.

Because of the discrepancy, the motion contends, any of Judge Wayne Salvant’s rulings should be tossed, including the decision that Couch must serve time behind bars. The details of the motion were confirmed Wednesday morning by a member of Couch’s legal team to CBS DFW.

In May, Couch was transferred from a maximum security facility to a “less restrictive” location, but reportedly still spends much of his time in solitary confinement for his own protection.

His mother Tonya Couch is also facing charges after allegedly fleeing the country with her son. She is awaiting trial on hindering the apprehension of a felon and money laundering charges.