Witness testimony ended Tuesday in the trial of a former Uvalde, Texas, school police officer accused of failing in his duty to stop a gunman in the critical first minutes of the 2022 Robb Elementary School attack, setting up the case to go to the jury.

Defense lawyers for Adrian Gonzales rested their case after calling just two witnesses, including a police tactics expert to bolster their claim that Gonzales did the best he could after driving onto campus amid a chaotic scene.

Gonzales has pleaded not guilty to 29 counts of child abandonment or endangerment. He faces up to two years in prison if convicted.

Gonzales did not take the stand in his own defense. Closing arguments are scheduled Wednesday before the jury begins deliberations.

Prosecutors rested their case after nine day of testimony from 36 witnesses in a trial that began Jan. 5. Gonzales’ only two witnesses included a woman who worked across the street from the school who told jurors she saw the shooter ducking between cars and trying to stay out of view — testimony that could reinforce Gonzales’ claims that he never saw the gunman.

Jurors have heard at times gripping and emotional testimony from teachers who recounted the terrifying moments when the 18-year-old gunman entered the school and killed 19 students and two teachers. Prosecutors have presented graphic photos from inside the classrooms and brought to the witness stand officers who described the chaos of the response.

The prosecution’s case has tugged at the raw emotion and shock of the carnage of May 24, 2022, as they attempt to show what could have been avoided had Gonzales intercepted the gunman in the early seconds of the attack.

Prosecutors allege the 52-year-old Gonzales, a 10-year police veteran who had led an active shooter response training course two months before the shooting, abandoned his training and did not try to stop gunman Salvador Ramos before he entered the school.

“Every second counts in an active shooter situation.” special prosecutor Bill Turner said Tuesday, drilling down on 3 minutes between when Gonzales first arrived and when he went into the building. “Every second, more victims can die if a police officer is standing and waiting.”

Gonzales, however, has insisted he didn’t freeze in the chaotic early moments and never saw the gunman. His lawyers insist three officers on the other side of the school saw the gunman still outside and didn’t fire a shot. Body camera footage shows Gonzales being among the first group of officers to enter a shadowy and smokey hallway trying to reach the killer in a classroom.

The trial in Corpus Christi, Texas, is a rare case of a police officer charged with failing to stop a criminal act to protect lives.