In 2015, Couch violated the terms of his probation and fled to Mexico with his mother, Tonya Couch.
A judge agreed with the psychologist's call for leniency, and instead of sentencing the teen to prison (he could have gotten as much as 20 years), ordered him instead to a secure rehabilitation facility for an unspecified period of time, as well as giving him probation.
Killed were Breanna Mitchell, 24, of Lillian, whose auto had broken down; Hollie Boyles, 52, and Shelby Boyles, 21, who lived nearby and had come outside to help Mitchell; and Burleson youth minister Brian Jennings, 41, a passer-by who had also stopped to help.
A psychologist at his manslaughter trial in Texas argued Couch suffered from "affluenza", having been raised without rules because of his parents' wealth.
The then-16-year-old had a blood alcohol level three times the legal limit for adult drivers when he hit and killed four people with his pickup truck.
On June 15, 2013 Couch was behind the wheel of his father's red For F-350 pick-up, speeding 70mph down the road from his home in Burleson, Texas, where he had hosted a drunken teenage party.
Escorted by his attorney, Couch, 20, was released from jail Monday morning as dozens of media outlets - both local and national media - greeted him as he left the Tarrant County Community Supervision and Corrections Department.
Couch will remain under supervision that includes a Global Positioning System ankle monitor and frequent drug and alcohol testing, officials said.
One man also shared what he's learned about Couch during frequent jail visits.
He skirted jail when a juvenile court in 2014 sentenced him to 10 years of probation, sparking public outrage.
Couch's mother was arrested last week after failing a test for drugs and alcohol.
In addition to the four killed, nine were injured, several critically.
She told reporters that today would be a tough day for the victims' families.
"As an organization, we'll be there to serve them if they need us. He has a curfew so he can not out anytime between 9 p.m.to 6 a.m." said Kate Delaney. He'll also have a video-equipped interlock ignition device installed in his vehicle, so he can't start his auto without passing a breathalyzer test.
"He's got to have that Global Positioning System monitoring, he's got to have that anklet around him". I don't want to figure out how I can get around my probation.