The Uvalde Consolidated Independent School District announced Friday that it is suspending its entire police department.
Lt. Miguel Hernandez has been placed on administrative leave, while others are either retiring or filling other roles within the district.
The department is under investigation for its response to the May 24 mass shooting at Robb Elementary.
Nineteen students and two teachers were killed in the shooting.
While the state investigation is ongoing, the district said "recent developments have uncovered additional concerns with department operations."
The district said it has requested additional state troopers to patrol schools.
It plans to rebuild the school police department after the state report is filed, which is expected later this month.
The district said it will review the findings and hire a new chief.
The previous chief was fired following the mass shooting.
Pete Arredondo faced criticism for not ordering officers to go into the room where the gunman was holed up.
Officers waited more than an hour before breaching the classroom and killing the gunman.