Families of the children and teachers killed in the Uvalde, Texas, school massacre are renewing demands for criminal charges after a scathing Justice Department report again laid bare numerous failures by police during one of the deadliest classroom shootings in U.S. history.

“I’m very surprised that no one has ended up in prison,” said Velma Lisa Duran, whose sister Irma Garcia was one of the two teachers killed in the May 24, 2002, shooting. “It’s sort of a slap in the face that all we get is a review … we deserve justice.”

The release of the nearly 600-page report Thursday — roughly 20 months after the shooting — leaves a criminal investigation by Uvalde County prosecutors as one the last unfinished reviews by authorities into the attack at Robb Elementary School. Nineteen students and two teachers were killed inside two fourth-grade classrooms, while highly armed police officers waited in the hallways for more than hour before going inside to confront the gunman.