BROWNSVILLE – The trial for Ruben Torres is underway. He’s charged with killing 13-year-old Abigail Estrada of Harlingen.

The jury selection for the trial began Monday morning and opening statements are expected to begin on Tuesday.

The teen’s body has not been recovered.

Estrada was reported missing in June 2007. She was reportedly last seen with Torres, who was 16 at the time. The two were in a relationship.

An arrest warrant used to charge Torres in 2015 says Estrada was a key witness in a drive-by shooting. She was the driver and Torres was the shooter.

Estrada’s mother sent her to stay with relatives in Austin shortly after the shooting because Torres was making threats against her.

She eventually came back to Harlingen to celebrate Torres’s birthday. The arrest warrant says Torres and a friend went to pick Estrada up from her apartment. She never came home.

Torres was charged with her disappearance, and then the charges were dropped for lack of evidence.

A few years went by and the case eventually went cold.

Estrada’s family pushed on and continued to search for answers. Her aunt in Austin was the most vocal and represented the family.

She held memorials for Estrada on the day of her disappearance.

In early 2015, the Cameron County District Attorney’s Office was on to new leads. A handful of witnesses were interviewed.

The arrest warrant says Torres told one of his relatives he killed Estrada because she was a witness against him in the shooting.

Prosecutors gathered enough probable cause to get an arrest warrant. Torres was arrested and charged in Aug. 2015.

He went before a juvenile judge, since he was 16 when he allegedly committed the crime. The judge moved the case to district court where Torres was officially charged with Estrada’s murder as an adult.

Torres pleaded not guilty to the charges in 2016. He was given no bond and remains in the Cameron County jail.

The trial is scheduled to continue Tuesday at 10 a.m.