The U.S. Justice Department said on Sunday it will review law enforcement’s response to the school shooting in Uvalde, Texas, that killed 19 children and two teachers, amid growing anger over why police failed to swiftly confront the gunman.

Uvalde’s law enforcement officers allowed the shooter into Robb Elementary School and remained there for close to an hour. Officers waited in the corridor while panicked children called 911.

The Texas county and state authorities have announced that they will conduct their own investigation. Anthony Coley, a spokesman for the Justice Department, said it will conduct a “Critical Incident Review” of law enforcement’s response to the shooting at the request of Uvalde’s mayor.

Coley explained that “the goal of this review is to provide an objective account of law enforcement activities and responses that day and to identify lessons learnt and best practices in order to help first responders prepare to and respond during active shooter incidents.”

“The Justice Department will publish a report with its findings at the conclusion of its review,” Coley added.