(CNN)A Texas judge on Friday recommended that "affluenza" teenager Ethan Couch's probation for a 2013 fatal drunken-driving crash be transferred from juvenile court to adult court -- a long-expected move that prosecutors say could see him serve more jail time.
'Affluenza' teen Ethan Couch's case sent to adult court
At its core, the decision in Tarrant County juvenile court should ensure that Couch's eight remaining years of probation won't evaporate when he turns 19 in April.
But Couch, already jailed after he and his mother were arrested in Mexico in December on suspicion of trying to avoid a probation hearing, should serve a minimum 120 days extra days behind bars, prosecutors say.
That's not punishment for the Mexico arrest, but a provision of state law for certain young probationers moving to the adult system, according to prosecutors.
"We have been waiting for this day for the last two years, and we're very pleased with the court's ruling," Tarrant County Prosecutor Riley Shaw said Friday.
The case of Couch, convicted of manslaughter in the deaths of four people in a drunken-driving crash in 2013 when he was 16, made national news when a judge sentenced him to 10 years of probation instead of jail time.
During the trial, his lawyers cited the now notorious "affluenza" defense, suggesting he was too rich and spoiled to understand the consequences of his actions.
On Friday, Couch, wearing a red jail jumpsuit, said little as Judge Timothy Menikos recommended that an adult court take over the supervision of his probation when he turns 19 on April 11.
Relatives of the crash victims were among those in the packed courtroom. "Victory in Jesus' name!" exclaimed one woman who'd been sitting with the victims' relatives.
An adult court judge, in a hearing yet to be scheduled, will determine conditions for the probation, such as curfews and electronic monitors.
Shaw said state law requires that one condition be jail time.
"When this case becomes an adult case ... there is a requirement for 120 days in jail as a condition of probation, and we would expect the (adult) court to impose that," Shaw said.
The maximum, Couch's attorney Scott Brown said, is 180 days for a transitioning probationer convicted of a second-degree felony like Couch.
Couch has been detained in Tarrant County since late January, when U.S. authorities escorted him back to the country from Mexico.
Since earlier this month, he has been in solitary confinement in an adult jail. Menikos ordered that he remain jailed until the adult court hearing.
Prosecutors will seek no further punishment for alleged probation violations as a juvenile, Shaw said, because the time for that runs out when he turns 19.
But a judge can take Couch's juvenile probation record into account when setting conditions for his adult probation, Shaw said.
Shaw added that he believes the judge shouldn't credit Couch with jail time already served as a juvenile.
Prosecutor Richard Alpert has said that authorities will closely watch Couch after his release and would move swiftly to revoke his probation should he violate it.
In mid-December, a Texas warrant was issued for Couch to be taken into custody after his probation officer couldn't reach him. He appeared to have dropped off the radar after a video emerged that allegedly showed him at a party where alcohol was consumed.
Couch had been ordered to stay away from drugs and alcohol for the duration of his probation.
Authorities say Couch and his mother, Tonya Couch, fled to Mexico to avoid a probation hearing that might have led to jail time for him.
Mexican authorities detained the mother and the son later that month in a Pacific resort town.
Tonya Couch, who, like her son, was returned to the United States, has been charged with hindering her son's apprehension and is free on $75,000 bond, CNN affiliate KTVT reported.