Brownsville, TX (KRGV) — Opening statements began Tuesday in Brownsville in the trial of a man accused of killing a tow truck driver in a Harlingen crash last year.

Cristobal Stephan Garzez is on trial in the July 8, 2025, death of 46-year-old David Zapata of Mercedes. The trial moved into testimony Tuesday after Monday's jury selection.

The Texas Department of Public Safety says Zapata was on the shoulder of the expressway securing a vehicle to his tow truck when a white Dodge Ram driven by Garzez did not slow down and hit him. DPS says Garzez left the scene, but officers found him near the crash site.

According to a criminal complaint obtained by Channel 5 News, Garzez told officers he did not stop because he was “scared.” The complaint also says officers found blood on the passenger door of his truck and a white baggy with 1.26 grams of a white powdery substance inside the vehicle.

The complaint says Garzez had constricted pupils and a trooper believed he was under the influence of narcotics. 

Martin Montez testified through an interpreter that he saw Garzez's white truck hit Zapata's tow truck and keep going. Montez said the lane ahead of Garzez was clear and there was no reason for the truck to move onto the shoulder.

Joel Ruiz testified that he was driving right behind Garzez and was the first person to pull over, call 9-1-1 and try to help. Ruiz said the tow truck was visible and fully on the shoulder when Garzez veered over, hit it, moved back into the right lane, and kept driving.

Ruiz said he saw Sergio Ortega, Zapata’s coworker, dive out of the way. Ruiz testified that when he went to render aid, he saw Zapata was already dead and found Ortega in shock, repeating, "That was my boss! That was my boss!" and saying he needed to call Zapata's wife.

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Ruiz also said he tried to calm Ortega because he is a licensed social worker and later had nightmares about the crash.

Ortega testified that he worked with Zapata on dangerous towing jobs and directed traffic while Zapata loaded vehicles. Ortega said there was plenty of room between the shoulder and the right lane, adding that Zapata never stepped into traffic and the tow truck’s emergency lights were flashing.

During cross-examination, Ortega said Zapata was not wearing a reflective vest and had on black clothes. Ortega also said the tow truck was black, the tires being tied down were black, and the Dodge Ram on the tow truck bed blocked the flashing lights.

La Feria Police Sgt. Raul Diaz testified that he was the first officer to reach Garzez. Diaz said Garzez seemed relaxed, walked heavily, spoke slowly, and looked intoxicated.

Diaz said he found a lighter and pieces of foil on Garzez and that Garzez admitted he hit a vehicle. During cross-examination, the defense questioned why Diaz did not include those observations in his report or update it later.

DPS Trooper Karen Treto testified that Garzez seemed confused but calm and did not make direct eye contact. Treto said she saw fresh blood and human tissue on the right side of his truck, and jurors watched body camera and patrol car videos from the scene.

Treto testified that Garzez told her he was in the right lane and was trying to move left because traffic was slowing down. She also said she recommended a blood test and that DPS Trooper Jesus Molina handled the testing.

Garzez faces charges of intoxication manslaughter, manslaughter, and possession of a controlled substance, which an indictment identifies as fentanyl.

Testimony continues on Wednesday.