A judge in Texas on Monday reduced the bond for the mother of a teenager who used an "affluenza" defense after killing four people in a drunken driving wreck.

Judge Wayne Salvant lowered Tonya Couch's bond from $1 million to $75,000 saying, "We're talking about a third degree felony here - not capital murder. Let's look at it for what it is."

Officials had sent Tonya Couch back to Texas last week after she was caught with 18-year-old Ethan Couch in the Mexican resort town of Puerto Vallarta.

Testifying about her finances, Steven McWilliams, Tonya Couch's son from a previous relationship, said authorities had frozen her bank accounts, displaying a balance of “negative 99 billion” dollars online. He said his mother could not afford to pay a bond of $1 million.

The judge added conditions to her bond. Tonya Couch will need to report to a probation officer and submit to drug and alcohol tests. She also must pay back more than $3,000 in costs related to her extradition to Texas.

According to an arrest warrant, Tonya Couch had taken $30,000 from a bank account and told Ethan's father he would never see them again before she and her son left for Mexico. They fled after Ethan Couch was accused of potentially violating his probation.

His case drew national attention and derision when he was sentenced to 10 years' probation for a 2013 drunken driving wreck that killed four people and injured several others, including passengers in his pickup truck.

A defense witness argued that Couch had been coddled by his wealthy parents, a condition the expert called "affluenza." The condition is not recognized as a medical diagnosis by the American Psychiatric Association, and its invocation drew ridicule.

Law enforcement officials say Tonya, 48, and Ethan, 18, fled to Mexico after a video surfaced that appeared to show the teen at a party drinking alcohol. If he was also drinking, it would violate his probation and could lead to jail time.

Law enforcement officials believe the mother and son had a going away party shortly before driving across the border in her pickup truck, making their way to Puerto Vallarta. They were first tracked to a resort condominium after ordering pizza. They had moved on by the time authorities arrived, but a witness directed police to an apartment in Puerto Vallarta's old town.

When they were arrested, authorities said Ethan Couch appeared to have tried to disguise himself by dying his blond hair black and his beard brown.

Telephone and email messages left with the Tarrant County sheriff's office and Tonya Couch attorney Stephanie Patten were not immediately returned Saturday.

According to the arrest warrant affidavit, Ethan Couch was "scared" after the video surfaced and did not respond to a Dec. 3 call from his probation officer to report for a drug test. He also did not appear for a scheduled meeting with the officer on Dec. 10.

A search warrant of bank and phone records found Tonya Couch had withdrawn $30,000 from a personal account and there was no other activity after Dec. 3. That day she also called her former husband Fred Couch to say he would never see them again.

Phone numbers used by the mother and son were no longer active after that date, according to the warrant.

Fred and Tonya Couch divorced in 2006. Authorities have previously said they had no evidence Fred Couch, who owns a North Texas sheet metal factory, was involved in helping Tonya and Ethan Couch flee.

Fox News' Casey Stegall and The Associated Press contributed to this report.