Authorities said they determined the child was left alone for about 30 minutes.
The chain of events, captured on video, began when the family's Uber driver went after a truck that rear-ended them and crashed out. Now, the young victim is fighting for her life, and her family says they haven't received any answers on their case.
The morning of the deadly crash, Keith Brazier was released on parole for multiple drunk driving convictions. He hit the bars in Galveston to celebrate, and by that evening, he was back in custody.
According to court documents, the weapon was within "easy" reach of both children. Documents show that the children are ages 2 and 4 years old.
The baby was taken to the hospital in critical condition after the crash at the intersection of North Shepherd and Tidwell, where police say the traffic lights weren't working.
The now-former deputy faces several charges for allegedly leaving his 2-month-old in the car for about three hours after a pediatrics appointment. The baby remains in critical condition.