Story highlights A judge has issued a warrant to have Couch detained, his lawyers say

Ethan Couch's probation officer has not been able to reach him or Couch's mother

Couch was convicted two years ago at age 16 of killing four people while driving drunk

(CNN) A warrant has been issued to take a teenager into custody who, two years ago, made national news when he was sentenced to probation in Texas for a drunken driving crash that killed four people. Ethan Couch's defense coined an infamous defense -- that he suffered from "affluenza," or that he was a rich kid who was less to blame for his crime because his parents didn't set limits for him.

Ethan Couch's probation officer couldn't reach him this week, Couch's lawyers told CNN. Couch's mother, with whom the 18-year-old lives, is also missing, said Scott Brown and William Reagan.

Under the terms of his probation, Couch isn't supposed to lose contact with his probation officer, his lawyers said.

Their apparent disappearance comes shortly after a video turned up on social media that allegedly shows Couch at a party where alcohol is being consumed, CNN affiliate KTVT reported.

When asked to confirm Couch's attendance at the party, his attorneys told CNN's sister network HLN they "are aware that the probation authorities and/or the District Attorney's office are conducting an investigation to determine if Ethan has violated any of the terms and conditions of his probation. It would not be prudent for us to make any further statement on Ethan's behalf until the investigations are concluded and it is determined what, if any, action will be taken against him."

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