probation officer who has a lot of questions but couch is m.i.a. an arrest warrant is out on him and he may be on the run with his mother. yes, his mother. in fact, the actions of both parents have shocked a lot of people. randi kaye reports. >> reporter: soon after then 16-year-old ethan couch got drunk, drove, killed four people, and injured several others, he and his parents testified in a civil suit brought by one of the victims. in these 2013 deposition tapes obtained by abc news, ethan couch talks openly about his drug use. >> taken valium hydrocodone, marijuana, cocaine, xanax, vivans. i've tried ecstasy once. >> reporter: where did it all go wrong? early and often, it seems. with a defense witness and psychologist placing the blame squarely at the feet of ethan's parents. >> ethan learned you should be able to do what you want to do