A Texas teenager who made headlines for all the wrong reasons after he was sentenced to probation in the drunken driving deaths of four people has gone missing.

Said to be suffering from "affluenza" by a psychologist testifying in his defense, Ethan Couch was just 16 when the wreck occurred. As a condition of his probation, Couch was instructed to not lose touch with his probation officer, and to stay from drugs or alcohol. Violation of his probation could result in a jail sentence of 10 years.

A video surfaced recently that allegedly showed Couch at a party with alcohol, possibly playing beer pong, a violation of the terms of his probation.

Local authorities immediately launched a search for Couch, now 18. A warrant was issued for his arrest this week.

Here are three things to know about the case:

1. The FBI and US Marshalls have joined in the search - Tarrant (Texas) County Sheriff Dee Anderson said Thursday that Couch can run, but he can't hide.

"You can run, but you're always going to be looking over your shoulder. We're not going to give up. We're going to come after you. We're going to find you, wherever you are."

If and when Couch is apprehended, a hearing will be held to determine what will happen to him, including whether his case will be moved from juvenile court to adult court once he turns 19.

2. His mother is also missing - In spite of the fact that many have blamed his parents for spoiling him, Couch has been living under the care of his mother, Tonya Couch. She is also missing.

Authorities are concerned the pair may have fled the country because they have the means to do so, and evidence exists that they have not been home in several days. Tonya Couch has not been charged with anything.

As part of his defense, Ethan Couch's attorneys emphasized his boundary-less upbringing, and the fact that his parents have their own problems.

Ethan's father Fred owns a profitable sheet metal company. Since 1989 his father has shown up in police reports 23 times, and his mother was charged with reckless driving in 2003. His parents divorced in 2007.

“I hate to say I told you so, but I told you so,” Anderson has said.

3. There is a fifth victim - On the night of the crash, Ethan and some friends had stolen beer from Walmart. Ethan Couch's blood alcohol was three times the legal limit when the truck he was driving plowed into a group of people gathered around a stalled vehicle.

The impact killed Shelbie Boyles, her mother Hollie, their friend Breanna Mitchell and a passerby and pastor, Brian Jennings, who stopped to help.

Ethan Couch's pickup was carrying several people, including Sergio Molina, who is paralyzed and can only communicate by blinking.

His medical expenses are expected to exceed $10 million. He has received a settlement in excess of $2 million from the Couch family.