EL PASO, Texas (Border Report) — Law enforcement officers noticed the fuel tank of a woman’s Ford Explorer had been tampered with and removed when they stopped her.

A closer look revealed 12 concealed bundles of what turned out to be more than 85 pounds of meth and heroin.

Police arrested 27-year-old Cristina Inez Marquez on Dec. 29, 2021, near Alice, Texas, about 120 miles north of the U.S-Mexico border.

On Thursday, the Mission, Texas, woman pleaded guilty to knowingly transporting and possessing over 31 kilograms of meth and five kilograms of heroin.

Prosecutors said an analysis of the drugs found the meth was 95% pure. With the 6 kilos of black tar heroin, the drugs had an estimated street value of more than $1.3 million.

Marquez will be sentenced on July 20. She faces a sentence of up to life in prison and a possible $10 million maximum fine.

She has been and will remain in custody pending sentencing.

The Drug Enforcement Administration conducted the investigation, and Assistant U.S. Attorney John Marck is prosecuting the case, according to a news release from the U.S. Attorney’s Office for the Southern District of Texas.