The teenager known for using an "affluenza" defense in a fatal drunken-driving wreck was returned to Texas on Thursday following his deportation from Mexico. Authorities believe 18-year-old Ethan Couch fled with his mother as Texas prosecutors investigated whether he violated his probation in the 2013 wreck that killed four people.

Here is a timeline of events in the case:

— June 15, 2013: Four people are killed when a pickup truck driven by 16-year-old Ethan Couch swerves off a road in Fort Worth, Texas. Couch's blood-alcohol level is three times the legal limit for driving. The victims are a woman whose vehicle was disabled on the side of the road and three people helping her. Two of the seven passengers in Couch's truck are severely injured.

— Dec. 4, 2013 — Couch "admitted his guilt" in juvenile court in four cases of intoxication manslaughter and two cases of intoxication assault, according to the Tarrant County Criminal District Attorney's Office.

— Dec. 10, 2013: A defense witness testifies during Couch's sentencing that the teen's wealthy parents coddled him into a sense of irresponsibility, a condition the psychologist termed "affluenza." Couch is later ordered to rehab and sentenced to 10 years' probation, which prosecutors and law enforcement blasted as too weak.

— Feb. 5, 2014 — A juvenile court judge sets probation conditions that include barring Couch from driving and from drinking alcohol or using drugs.

— August 2015 — Couch's father files for divorce, a year after he and his wife stopped living together as a couple. Fred and Tonya Couch originally married in 1996. They divorced 10 years later, but then remarried in April 2011.

— On or about Dec. 2, 2015 — A video surfaces that shows Ethan Couch at a party where alcohol was being served. Drinking alcohol would be a violation of his probation.

— Dec. 3, 2015 — Couch is contacted by his probation officer and told to report for a drug test. His mother withdraws $30,000 from her personal account. On or around the same date, mother and son hold a gathering in which they talk about going to Mexico, and Fred Couch tells authorities that Tonya Couch had called to tell him he would never see their son again.

— Dec. 10, 2015 — Ethan Couch, who is now 18, misses a mandatory appointment with his probation officer.

— Dec. 11, 2015 — A directive to apprehend Couch for a probation violation is issued.

— Dec. 16, 2015 — Authorities publicly announce they're investigating whether Couch fled with his mother in an attempt to avoid facing accusations that he may have violated his probation.

— Dec. 28, 2015 — Ethan Couch and Tonya Couch are taken into custody in the Mexican resort city of Puerto Vallarta, a few days after a call for pizza delivery tipped off authorities to their whereabouts. Texas authorities issue an arrest warrant for Tonya Couch.

— Dec. 30, 2015 — Tonya Couch is deported, but a Mexican judge decides to delay Ethan Couch's deportation. Tonya Couch arrives on a flight early the next morning in Los Angeles, where she is taken to jail.

— Jan. 7, 2016 — Law enforcement officers accompany Tonya Couch as she is flown back to Texas. She is booked at the Tarrant County Jail in Fort Worth.

— Jan. 8, 2016 — Tonya Couch is arraigned on a charge of hindering the apprehension of a felon. Her bond is set at $1 million.

— Jan. 11, 2016 — A judge lowers Tonya Couch's bond to $75,000. She posts the bond the next day and is released to live with another son, after being fitted with an electronic ankle GPS monitor.

— Jan. 17, 2016 — Ethan Couch's attorney in Mexico files a document seeking to lift the injunction that has kept him in Mexico.

— Jan. 25, 2016 — Ethan Couch formally ratifies his decision to drop an appeal against deportation.

— Jan. 28, 2016 — Ethan Couch is deported and flown on a commercial flight from Mexico City to Dallas-Fort Worth International Airport. He is booked at a juvenile detention facility.