Families who lost loved ones in the 2022 attack on an elementary school in Uvalde, Texas, have sought for nearly four years to hold accountable the police who waited more than an hour to confront the shooter while children and teachers lay dead or wounded in classrooms.

Now one of the first officers on the scene is about to stand trial on multiple charges of child abandonment and endangerment. Former Uvalde schools police officer Adrian Gonzales is accused of ignoring his training in a crisis with deadly consequences. His attorney insists he was focused on helping children escape from the building.

The trial that starts Monday offers potentially one of the last chances to see police answer for the long delay. The families have pinned their hopes on the jury after their gun-control efforts were rejected by lawmakers, and their lawsuits remain unresolved. A few parents ran for political office to seek change, with mixed results.