Texas Officials Move 'Affluenza Teen' Ethan Couch to Adult Jail

Ethan Couch – the 18-year-old Texas man known as the "affluenza teen" – has been transferred to an adult jail after spending a week in a juvenile detention center, PEOPLE confirms.

A source at the Tarrant County Sheriff's Office tells PEOPLE that Couch was moved Friday from the Lynn Ross Juvenile Detention Center in Fort Worth, Texas, to the Tarrant County Jail four miles away.

"He's an adult," Sheriff Dee Anderson told reporters during a press conference Friday afternoon. Couch will turn 19 in April.

"He doesn't need to be housed in a juvenile detention facility," Anderson added. "That's my opinion."

Couch has been in the custody of Texas police since Jan. 28, after being extradited from Mexico.

• Want to keep up with the latest crime coverage? Click here to get breaking crime news, ongoing trial coverage and details of intriguing unsolved cases in the True Crime Newsletter.

Mexican authorities had detained Couch and his mother a little more than two months ago in the resort town of Puerto Vallarta. The mother and son spent weeks on the run, allegedly fleeing the United States after learning detectives were investigating Couch for possible probation violations.

At 16, Couch killed four pedestrians in a 2013 drunk driving accident. He was spared jail time and sentenced to probation after his defense attorney successfully argued his client suffered from "affluenza," suggesting his wealthy upbringing had rendered him incapable of understanding the repercussions of his actions.

Couch and his mother allegedly went on the lam after potentially incriminating video footage was posted to Twitter, showing Ethan allegedly attending a party where drinking games were being played.

Couch's 10-year probation sentence prohibits him from driving a car, doing drugs or drinking alcohol.

The U.S. Marshals Service tracked Couch and his mother to a Mexico apartment, where one of them used a cell phone to call Domino's Pizza.

Couch's mother has been charged by Texas authorities with hindering the apprehension of her fugitive son and was released earlier this month on $75,000 bail.

The terms of her release call for Couch to wear an electronic monitoring bracelet. She must also live at her older son's home, a judge ruled.